diff --git a/FileProvider.podspec b/FileProvider.podspec
index d4609ba..92765e1 100644
--- a/FileProvider.podspec
+++ b/FileProvider.podspec
@@ -16,7 +16,7 @@ Pod::Spec.new do |s|
   #
 
   s.name         = "FileProvider"
-  s.version      = "0.12.1"
+  s.version      = "0.12.2"
   s.summary      = "FileManager replacement for Local and Remote (WebDAV/Dropbox/OneDrive/SMB2) files on iOS and macOS."
 
   # This description is used to generate tags and improve search results.
diff --git a/FileProvider.xcodeproj/project.pbxproj b/FileProvider.xcodeproj/project.pbxproj
index 83d83cc..0b2ace8 100644
--- a/FileProvider.xcodeproj/project.pbxproj
+++ b/FileProvider.xcodeproj/project.pbxproj
@@ -603,7 +603,7 @@
 		799396601D48B7BF00086753 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				BUNDLE_VERSION_STRING = 0.12.1;
+				BUNDLE_VERSION_STRING = 0.12.2;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
 				CLANG_WARN_EMPTY_BODY = YES;
@@ -633,7 +633,7 @@
 		799396611D48B7BF00086753 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				BUNDLE_VERSION_STRING = 0.12.1;
+				BUNDLE_VERSION_STRING = 0.12.2;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
 				CLANG_WARN_EMPTY_BODY = YES;
diff --git a/README.md b/README.md
index d150377..ac483ef 100644
--- a/README.md
+++ b/README.md
@@ -31,15 +31,15 @@ Local and WebDAV providers are fully tested and can be used in production enviro
 - [x] **LocalFileProvider** a wrapper around `FileManager` with some additions like searching and reading a portion of file.
 - [x] **CloudFileProvider** A wrapper around app's ubiquitous container to iCloud Drive in iOS 8+ API.
 - [x] **WebDAVFileProvider** WebDAV protocol is defacto file transmission standard, replaced FTP.
-- [x] **DropboxFileProvider** A wrapper around Dropbox REST API.
+- [x] **DropboxFileProvider** A wrapper around Dropbox Web API.
     * For now it has limitation in uploading files up to 150MB.
 - [x] **OneDriveFileProvider** A wrapper around OneDrive REST API, works with `onedrive.com` and compatible (business) servers.
     * For now it has limitation in uploading files up to 100MB.
 - [ ] **GoogleFileProvider** A wrapper around Goodle Drive REST API.
 - [ ] **AmazonS3FileProvider** Amazon storage backend. Used by many sites.
 - [ ] **SMBFileProvider** SMB2/3 introduced in 2006, which is a file and printer sharing protocol originated from Microsoft Windows and now is replacing AFP protocol on macOS.
-    * Data types and some basic functions are implemented but *main interface is not implemented yet!*
-    *  SMB1/CIFS is depericated and very tricky to be implemented
+    * Data types and some basic functions are implemented but *main interface is not implemented yet!*.
+    * SMB1/CIFS is deprecated and very tricky to be implemented.
 - [ ] **FTPFileProvider** while deprecated in 1990s, it's still in use on some Web hosts.
 
 ## Requirements
@@ -69,7 +69,7 @@ github "amosavian/FileProvider"
 Or to use in Swift Package Manager add this line in `Dependencies`:
 
 ```swift
-.Package(url: "https://github.com/amosavian/FileProvider.git", majorVersion: 0, minorVersion: 8)
+.Package(url: "https://github.com/amosavian/FileProvider.git", majorVersion: 0, minorVersion: 12)
 ```
 
 ### Manually
diff --git a/Sources/CloudFileProvider.swift b/Sources/CloudFileProvider.swift
index 42965a6..c9204a4 100644
--- a/Sources/CloudFileProvider.swift
+++ b/Sources/CloudFileProvider.swift
@@ -11,7 +11,8 @@ import Foundation
 open class CloudFileProvider: LocalFileProvider {
     open override class var type: String { return "iCloudDrive" }
     
-    /// Actually is readonly, value is true
+    /// Forces file operations to use `NSFileCoordinating`,
+    /// Actually this is readonly, and value is always true.
     override open var isCoorinating: Bool {
         get {
             return true
@@ -24,6 +25,9 @@ open class CloudFileProvider: LocalFileProvider {
     /// The fully-qualified container identifier for an iCloud container directory.
     open fileprivate(set) var containerId: String?
     
+    /// Scope of container, indicates user can manipulate data/files or not.
+    open fileprivate(set) var scope: UbiquitousScope
+    
     /**
      Initializes the provider for the iCloud container associated with the specified identifier and 
      establishes access to that container.
@@ -31,10 +35,11 @@ open class CloudFileProvider: LocalFileProvider {
      - Important: Do not call this method from your app’s main thread. Because this method might take a nontrivial amount of time to set up iCloud and return the requested URL, you should always call it from a secondary thread.
      
      - Parameter containerId: The fully-qualified container identifier for an iCloud container directory. The string you specify must not contain wildcards and must be of the form `<TEAMID>.<CONTAINER>`, where `<TEAMID>` is your development team ID and `<CONTAINER>` is the bundle identifier of the container you want to access.\
-     The container identifiers for your app must be declared in the `com.apple.developer.ubiquity-container-identifiers` array of the `.entitlements` property list file in your Xcode project.\
-     If you specify nil for this parameter, this method uses the first container listed in the `com.apple.developer.ubiquity-container-identifiers` entitlement array.
+         The container identifiers for your app must be declared in the `com.apple.developer.ubiquity-container-identifiers` array of the `.entitlements` property list file in your Xcode project.\
+         If you specify nil for this parameter, this method uses the first container listed in the `com.apple.developer.ubiquity-container-identifiers` entitlement array.
+     - Parameter scope: Use `.documents` (default) to put documents that the user is allowed to access inside a Documents subdirectory. Otherwise use `.data` to store user-related data files that your app needs to share but that are not files you want the user to manipulate directly.
     */
-    public init? (containerId: String?) {
+    public init? (containerId: String?, scope: UbiquitousScope = .documents) {
         assert(!Thread.isMainThread, "LocalFileProvider.init(containerId:) is not recommended to be executed on Main Thread.")
         guard FileManager.default.ubiquityIdentityToken == nil else {
             return nil
@@ -43,7 +48,14 @@ open class CloudFileProvider: LocalFileProvider {
             return nil
         }
         self.containerId = containerId
-        let baseURL = ubiquityURL.standardized.appendingPathComponent("Documents/")
+        self.scope = scope
+        let baseURL: URL
+        if scope == .documents {
+            baseURL = ubiquityURL.standardized.appendingPathComponent("Documents/")
+        } else {
+            baseURL = ubiquityURL.standardized
+        }
+        
         super.init(baseURL: baseURL)
         self.isCoorinating = true
         
@@ -57,12 +69,14 @@ open class CloudFileProvider: LocalFileProvider {
         try? fileManager.createDirectory(at: baseURL, withIntermediateDirectories: true)
     }
     
+    // FIXME: create runloop for dispatch_queue, start query on it
     open override func contentsOfDirectory(path: String, completionHandler: @escaping ((_ contents: [FileObject], _ error: Error?) -> Void)) {
         dispatch_queue.async {
             let pathURL = self.url(of: path)
+            
             let query = NSMetadataQuery()
             query.predicate = NSPredicate(format: "%K BEGINSWITH %@", NSMetadataItemPathKey, pathURL.path)
-            query.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope]
+            query.searchScopes = [self.scope.rawValue]
             var finishObserver: NSObjectProtocol?
             finishObserver = NotificationCenter.default.addObserver(forName: NSNotification.Name.NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
                 defer {
@@ -91,9 +105,14 @@ open class CloudFileProvider: LocalFileProvider {
                     }
                 }
                 
+                query.stop()
                 completionHandler(contents, nil)
             })
-            query.start()
+            DispatchQueue.main.async {
+                if !query.start() {
+                    completionHandler([], self.throwError(path, code: CocoaError.fileReadNoPermission))
+                }
+            }
         }
     }
     
@@ -107,7 +126,7 @@ open class CloudFileProvider: LocalFileProvider {
             let pathURL = self.url(of: path)
             let query = NSMetadataQuery()
             query.predicate = NSPredicate(format: "%K LIKE %@", NSMetadataItemPathKey, pathURL.path)
-            query.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope]
+            query.searchScopes = [self.scope.rawValue]
             var finishObserver: NSObjectProtocol?
             finishObserver = NotificationCenter.default.addObserver(forName: NSNotification.Name.NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
                 defer {
@@ -130,7 +149,11 @@ open class CloudFileProvider: LocalFileProvider {
                     completionHandler(nil, noFileError)
                 }
             })
-            query.start()
+            DispatchQueue.main.async {
+                if !query.start() {
+                    completionHandler(nil, self.throwError(path, code: CocoaError.fileReadNoPermission))
+                }
+            }
         }
     }
     
@@ -239,7 +262,7 @@ open class CloudFileProvider: LocalFileProvider {
             let pathURL = self.url(of: path)
             let query = NSMetadataQuery()
             query.predicate = NSPredicate(format: "(%K BEGINSWITH %@) && (%K LIKE %@)", NSMetadataItemPathKey, pathURL.path, NSMetadataItemFSNameKey, query)
-            query.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope]
+            query.searchScopes = [self.scope.rawValue]
             
             var lastReportedCount = 0
             
@@ -302,18 +325,22 @@ open class CloudFileProvider: LocalFileProvider {
                 completionHandler(contents, nil)
             })
             
-            query.start()
+            DispatchQueue.main.async {
+                if !query.start() {
+                    completionHandler([], self.throwError(path, code: CocoaError.fileReadNoPermission))
+                }
+            }
         }
     }
     
-    fileprivate var monitors = [URL: (NSMetadataQuery, NSObjectProtocol)]()
-    //
+    fileprivate var monitors = [String: (NSMetadataQuery, NSObjectProtocol)]()
+    
     open override func registerNotifcation(path: String, eventHandler: @escaping (() -> Void)) {
         self.unregisterNotifcation(path: path)
         let pathURL = self.url(of: path)
         let query = NSMetadataQuery()
         query.predicate = NSPredicate(format: "(%K BEGINSWITH %@)", NSMetadataItemPathKey, pathURL.path)
-        query.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope]
+        query.searchScopes = [self.scope.rawValue]
         
         let updateObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidUpdate, object: query, queue: nil, using: { (notification) in
             
@@ -324,24 +351,25 @@ open class CloudFileProvider: LocalFileProvider {
             query.enableUpdates()
         })
         
-        query.start()
-        
-        monitors[pathURL] = (query, updateObserver)
+        DispatchQueue.main.async {
+            if query.start() {
+                self.monitors[path] = (query, updateObserver)
+            }
+        }
     }
     
     open override func unregisterNotifcation(path: String) {
-        let key = url(of: path)
-        guard let (query, observer) = monitors[key] else {
+        guard let (query, observer) = monitors[path] else {
             return
         }
         query.disableUpdates()
         query.stop()
-        monitors.removeValue(forKey: key)
         NotificationCenter.default.removeObserver(observer)
+        monitors.removeValue(forKey: path)
     }
     
     open override func isRegisteredForNotification(path: String) -> Bool {
-        return monitors[url(of: path)] != nil
+        return monitors[path] != nil
     }
     
     open override func copy(with zone: NSZone? = nil) -> Any {
@@ -401,6 +429,38 @@ open class CloudFileProvider: LocalFileProvider {
     }
 }
 
+public enum UbiquitousScope: RawRepresentable {
+    /// Search all files not in the Documents directories of the app’s iCloud container directories.
+    /// Use this scope to store user-related data files that your app needs to share 
+    /// but that are not files you want the user to manipulate directly.
+    case data
+    /// Search all files in the Documents directories of the app’s iCloud container directories.
+    /// Put documents that the user is allowed to access inside a Documents subdirectory.
+    case documents
+    
+    public typealias RawValue = String
+    
+    public init? (rawValue: String) {
+        switch rawValue {
+        case NSMetadataQueryUbiquitousDataScope:
+            self = .data
+        case NSMetadataQueryUbiquitousDocumentsScope:
+            self = .documents
+        default:
+            return nil
+        }
+    }
+    
+    public var rawValue: String {
+        switch self {
+        case .data:
+            return NSMetadataQueryUbiquitousDataScope
+        case .documents:
+            return NSMetadataQueryUbiquitousDocumentsScope
+        }
+    }
+}
+
 open class CloudOperationHandle: OperationHandle {
     public let baseURL: URL?
     public let operationType: FileOperationType
@@ -458,11 +518,12 @@ open class CloudOperationHandle: OperationHandle {
     fileprivate static func getMetadataItem(url: URL) -> NSMetadataItem? {
         let query = NSMetadataQuery()
         query.predicate = NSPredicate(format: "(%K LIKE %@)", NSMetadataItemPathKey, url.path)
-        query.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope]
+        query.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope, NSMetadataQueryUbiquitousDataScope]
         
         var item: NSMetadataItem?
         
         let group = DispatchGroup()
+        group.enter()
         var finishObserver: NSObjectProtocol?
         finishObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
             defer {
@@ -479,8 +540,9 @@ open class CloudOperationHandle: OperationHandle {
             
         })
         
-        group.enter()
-        query.start()
+        DispatchQueue.main.async {
+            query.start()
+        }
         _ = group.wait(timeout: DispatchTime.now() + 30)
         return item
     }
diff --git a/Sources/DropboxFileProvider.swift b/Sources/DropboxFileProvider.swift
index 5c1331e..3bc01b4 100644
--- a/Sources/DropboxFileProvider.swift
+++ b/Sources/DropboxFileProvider.swift
@@ -133,8 +133,6 @@ open class DropboxFileProvider: FileProviderBasicRemote {
 }
 
 extension DropboxFileProvider: FileProviderOperations {
-    
-    
     public func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let path = (atPath as NSString).appendingPathComponent(folderName) + "/"
         return doOperation(.create(path: path), completionHandler: completionHandler)
@@ -244,7 +242,10 @@ extension DropboxFileProvider: FileProviderOperations {
 
 extension DropboxFileProvider: FileProviderReadWrite {
     public func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
-        if length == 0 {
+        if length == 0 || offset < 0 {
+            dispatch_queue.async {
+                completionHandler(Data(), nil)
+            }
             return nil
         }
         
@@ -305,12 +306,12 @@ extension DropboxFileProvider: FileProviderReadWrite {
         NotImplemented()
     }
     
-    // TODO: Implement /copy_reference, /get_account & /get_current_account
+    // TODO: Implement /get_account & /get_current_account
 }
 
 extension DropboxFileProvider {
     /// *DEPRECATED:* Use `publicLink(to:, completionHandler: (URL?, DropboxFileObject?, Date?,  Error?))` function instead.
-    @available(*, deprecated, message: "Use publicLink(to:, completionHandler: (URL?, DropboxFileObject?, Date?,  Error?)) function instead.")
+    @available(*, deprecated, renamed: "publicLink(to:completionHandler:)", message: "Use publicLink(to:, completionHandler: (URL?, DropboxFileObject?, Date?,  Error?)) function instead.")
     open func temporaryLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: DropboxFileObject?, _ error: Error?) -> Void)) {
         self.publicLink(to: path) { (url, file, _, error) in
             completionHandler(url, file, error)
@@ -318,7 +319,7 @@ extension DropboxFileProvider {
     }
     
     /// *DEPRECATED:* Use `publicLink(to:, completionHandler: (URL?, DropboxFileObject?, Date?,  Error?))` function instead.
-    @available(*, deprecated, message: "Use publicLink(to:, completionHandler: (URL?, DropboxFileObject?, Date?,  Error?)) function instead.")
+    @available(*, deprecated, renamed: "publicLink(to:completionHandler:)", message: "Use publicLink(to:, completionHandler: (URL?, DropboxFileObject?, Date?,  Error?)) function instead.")
     open func temporaryLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: DropboxFileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
         self.publicLink(to: path) { (url, file, expiration, error) in
             completionHandler(url, file, expiration, error)
diff --git a/Sources/FileObject.swift b/Sources/FileObject.swift
index aca297b..c6b0fa3 100644
--- a/Sources/FileObject.swift
+++ b/Sources/FileObject.swift
@@ -25,7 +25,7 @@ open class FileObject {
     }
     
     /// url to access the resource, not supported by Dropbox provider
-    @available(*, deprecated, message: "Use url.absoluteURL instead.")
+    @available(*, deprecated, renamed: "url", message: "Use url.absoluteURL instead.")
     open var absoluteURL: URL? {
         return url?.absoluteURL
     }
@@ -101,8 +101,8 @@ open class FileObject {
         }
     }
     
-    /// **DEPRECATED:** Use `type` property instead.
-    @available(*, deprecated, message: "Use type property instead.")
+    /// **OBSOLETED:** Use `type` property instead.
+    @available(*, obsoleted: 1.0, renamed: "type", message: "Use type property instead.")
     open var fileType: URLFileResourceType? {
         return self.type
     }
diff --git a/Sources/FileProvider.swift b/Sources/FileProvider.swift
index cd11f42..bd9750b 100644
--- a/Sources/FileProvider.swift
+++ b/Sources/FileProvider.swift
@@ -510,8 +510,8 @@ extension FileProviderBasic {
         return path.trimmingCharacters(in: pathTrimSet).addingPercentEncoding(withAllowedCharacters: .urlPathAllowed)!
     }
     
-    /// **DEPRECATED:** Use `url(of:).absoluteURL` instead.
-    @available(*, deprecated, message: "Use url(of:).absoluteURL instead.")
+    /// **OBSOLETED:** Use `url(of:).absoluteURL` instead.
+    @available(*, obsoleted: 1.0, renamed: "url(of:)", message: "Use url(of:).absoluteURL instead.")
     public func absoluteURL(_ path: String? = nil) -> URL {
         return url(of: path).absoluteURL
     }
@@ -534,11 +534,20 @@ extension FileProviderBasic {
         }
     }
     
+    
+    /// Returns the relative path of url, wothout percent encoding. Even if url is absolute or
+    /// retrieved from another provider, it will try to resolve the url against `baseURL` of
+    /// current provider. It's highly recomended to use this method for displaying purposes.
+    ///
+    /// - Parameter url: Absolute url to file or directory.
+    /// - Returns: A `String` contains relative path of url against base url.
     public func relativePathOf(url: URL) -> String {
-        if url.baseURL == self.baseURL {
+        // check if url derieved from current base url
+        if url.relativeString.isEmpty, url.baseURL == self.baseURL {
             return url.relativePath.removingPercentEncoding!
         }
         
+        // resolve url string against baseurl
         guard let baseURL = self.baseURL?.standardizedFileURL else { return url.absoluteString }
         return url.standardizedFileURL.absoluteString.replacingOccurrences(of: baseURL.absoluteString, with: "/").removingPercentEncoding!
     }
diff --git a/Sources/LocalFileProvider.swift b/Sources/LocalFileProvider.swift
index 4364629..eb3bbe3 100644
--- a/Sources/LocalFileProvider.swift
+++ b/Sources/LocalFileProvider.swift
@@ -417,7 +417,10 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor {
     
     @discardableResult
     open func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
-        if length == 0 {
+        if length == 0 || offset < 0 {
+            dispatch_queue.async {
+                completionHandler(Data(), nil)
+            }
             return nil
         }
         
diff --git a/Sources/LocalHelper.swift b/Sources/LocalHelper.swift
index e6fb140..70997c3 100644
--- a/Sources/LocalHelper.swift
+++ b/Sources/LocalHelper.swift
@@ -67,7 +67,7 @@ public final class LocalFileObject: FileObject {
 
 }
 
-internal class LocalFolderMonitor {
+internal final class LocalFolderMonitor {
     fileprivate let source: DispatchSourceFileSystemObject
     fileprivate let descriptor: CInt
     fileprivate let qq: DispatchQueue = DispatchQueue.global(qos: .default)
diff --git a/Sources/OneDriveFileProvide.swift b/Sources/OneDriveFileProvide.swift
index f381ff2..8b84a71 100644
--- a/Sources/OneDriveFileProvide.swift
+++ b/Sources/OneDriveFileProvide.swift
@@ -240,7 +240,10 @@ extension OneDriveFileProvider: FileProviderOperations {
 
 extension OneDriveFileProvider: FileProviderReadWrite {
     public func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
-        if length == 0 {
+        if length == 0 || offset < 0 {
+            dispatch_queue.async {
+                completionHandler(Data(), nil)
+            }
             return nil
         }
         
diff --git a/Sources/WebDAVFileProvider.swift b/Sources/WebDAVFileProvider.swift
index 7a61475..e83d3f8 100644
--- a/Sources/WebDAVFileProvider.swift
+++ b/Sources/WebDAVFileProvider.swift
@@ -331,7 +331,10 @@ extension WebDAVFileProvider: FileProviderOperations {
 extension WebDAVFileProvider: FileProviderReadWrite {
     @discardableResult
     public func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
-        if length == 0 {
+        if length == 0 || offset < 0 {
+            dispatch_queue.async {
+                completionHandler(Data(), nil)
+            }
             return nil
         }