diff --git a/package.json b/package.json
index 60850a905b..48c6dd7a8e 100644
--- a/package.json
+++ b/package.json
@@ -47,7 +47,7 @@
     "precommit": "lint-staged",
     "prettier": "prettier --write '**/*.{js,json,css}'",
     "prettier:ci": "prettier --check '**/*.{js,json,css}'",
-    "start": "cd ./shells/dev && opener ./index.html && webpack --config webpack.config.js --watch",
+    "start": "cd ./shells/dev && opener ./index.html && cross-env NODE_ENV=development webpack --config webpack.config.js --watch",
     "start:prod": "cross-env NODE_ENV=production npm start",
     "test": "jest",
     "test-debug": "node --inspect-brk node_modules/.bin/jest --runInBand",
diff --git a/shells/browser/shared/webpack.backend.js b/shells/browser/shared/webpack.backend.js
index 66554210c0..99249b3053 100644
--- a/shells/browser/shared/webpack.backend.js
+++ b/shells/browser/shared/webpack.backend.js
@@ -3,7 +3,13 @@ const { resolve } = require('path');
 const { DefinePlugin } = require('webpack');
 const { getGitHubURL, getVersionString } = require('../../utils');
 
-const __DEV__ = process.env.NODE_ENV === 'development';
+const NODE_ENV = process.env.NODE_ENV;
+if (!NODE_ENV) {
+  console.error('NODE_ENV not set');
+  process.exit(1);
+}
+
+const __DEV__ = NODE_ENV === 'development';
 
 const GITHUB_URL = getGitHubURL();
 const DEVTOOLS_VERSION = getVersionString();
diff --git a/shells/browser/shared/webpack.config.js b/shells/browser/shared/webpack.config.js
index 827d75a30c..8ff77ebc6e 100644
--- a/shells/browser/shared/webpack.config.js
+++ b/shells/browser/shared/webpack.config.js
@@ -4,6 +4,11 @@ const { DefinePlugin } = require('webpack');
 const { getGitHubURL, getVersionString } = require('../../utils');
 
 const NODE_ENV = process.env.NODE_ENV;
+if (!NODE_ENV) {
+  console.error('NODE_ENV not set');
+  process.exit(1);
+}
+
 const __DEV__ = NODE_ENV === 'development';
 
 const GITHUB_URL = getGitHubURL();
diff --git a/shells/dev/webpack.config.js b/shells/dev/webpack.config.js
index deb695ed44..7cd9c53b2a 100644
--- a/shells/dev/webpack.config.js
+++ b/shells/dev/webpack.config.js
@@ -3,7 +3,13 @@ const { resolve } = require('path');
 const { DefinePlugin } = require('webpack');
 const { getGitHubURL, getVersionString } = require('../utils');
 
-const __DEV__ = process.env.NODE_ENV === 'development';
+const NODE_ENV = process.env.NODE_ENV;
+if (!NODE_ENV) {
+  console.error('NODE_ENV not set');
+  process.exit(1);
+}
+
+const __DEV__ = NODE_ENV === 'development';
 
 const GITHUB_URL = getGitHubURL();
 const DEVTOOLS_VERSION = getVersionString();
diff --git a/src/backend/renderer.js b/src/backend/renderer.js
index a15771a1fc..09fc0881da 100644
--- a/src/backend/renderer.js
+++ b/src/backend/renderer.js
@@ -21,7 +21,7 @@ import {
   LOCAL_STORAGE_RELOAD_AND_PROFILE_KEY,
   TREE_OPERATION_ADD,
   TREE_OPERATION_REMOVE,
-  TREE_OPERATION_RESET_CHILDREN,
+  TREE_OPERATION_REORDER_CHILDREN,
   TREE_OPERATION_UPDATE_TREE_BASE_DURATION,
 } from '../constants';
 import { getUID } from '../utils';
@@ -938,7 +938,7 @@ export function attach(
 
     const numChildren = nextChildren.length;
     beginNextOperation(3 + numChildren);
-    nextOperation[0] = TREE_OPERATION_RESET_CHILDREN;
+    nextOperation[0] = TREE_OPERATION_REORDER_CHILDREN;
     nextOperation[1] = getFiberID(getPrimaryFiber(fiber));
     nextOperation[2] = numChildren;
     for (let i = 0; i < nextChildren.length; i++) {
diff --git a/src/constants.js b/src/constants.js
index ef69e21760..d64cc5da32 100644
--- a/src/constants.js
+++ b/src/constants.js
@@ -2,7 +2,7 @@
 
 export const TREE_OPERATION_ADD = 1;
 export const TREE_OPERATION_REMOVE = 2;
-export const TREE_OPERATION_RESET_CHILDREN = 3;
+export const TREE_OPERATION_REORDER_CHILDREN = 3;
 export const TREE_OPERATION_UPDATE_TREE_BASE_DURATION = 4;
 
 export const LOCAL_STORAGE_RELOAD_AND_PROFILE_KEY =
diff --git a/src/devtools/store.js b/src/devtools/store.js
index 267a8cecde..829f11b681 100644
--- a/src/devtools/store.js
+++ b/src/devtools/store.js
@@ -6,7 +6,7 @@ import throttle from 'lodash.throttle';
 import {
   TREE_OPERATION_ADD,
   TREE_OPERATION_REMOVE,
-  TREE_OPERATION_RESET_CHILDREN,
+  TREE_OPERATION_REORDER_CHILDREN,
   TREE_OPERATION_UPDATE_TREE_BASE_DURATION,
 } from '../constants';
 import { ElementTypeRoot } from './types';
@@ -733,12 +733,7 @@ export default class Store extends EventEmitter {
 
             const element = ((this._idToElement.get(id): any): Element);
             if (element.children.length > 0) {
-              throw new Error(
-                'Fiber ' +
-                  id +
-                  ' was removed before its children. ' +
-                  'This is a bug in React DevTools.'
-              );
+              throw new Error(`Node ${id} was removed before its children.`);
             }
 
             this._idToElement.delete(id);
@@ -775,10 +770,10 @@ export default class Store extends EventEmitter {
           }
           break;
         }
-        case TREE_OPERATION_RESET_CHILDREN: {
+        case TREE_OPERATION_REORDER_CHILDREN: {
           const id = ((operations[i + 1]: any): number);
           const numChildren = ((operations[i + 2]: any): number);
-          const children = ((operations.slice(
+          const nextChildren = ((operations.slice(
             i + 3,
             i + 3 + numChildren
           ): any): Array<number>);
@@ -786,7 +781,7 @@ export default class Store extends EventEmitter {
           i = i + 3 + numChildren;
 
           if (__DEBUG__) {
-            debug('Re-order', `Node ${id} children ${children.join(',')}`);
+            debug('Re-order', `Node ${id} children ${nextChildren.join(',')}`);
           }
 
           if (!this._idToElement.has(id)) {
@@ -797,22 +792,30 @@ export default class Store extends EventEmitter {
 
           const element = ((this._idToElement.get(id): any): Element);
           const prevChildren = element.children;
-          element.children = Array.from(children);
-          if (element.children.length !== prevChildren.length) {
-            throw new Error(
-              'Fiber ' +
-                id +
-                ' received a different number of children on reorder. ' +
-                'This is a bug in React DevTools.'
+          if (nextChildren.length !== prevChildren.length) {
+            throw Error(
+              `Children cannot be added or removed during a reorder operation.`
             );
           }
+          // This check is more expensive so it's gated
+          if (__DEV__) {
+            if (nextChildren.find(childID => {
+              const childElement = this._idToElement.get(childID);
+              return childElement == null || childElement.parentID !== id;
+            }) != null) {
+              console.error(
+                `Children cannot be added or removed during a reorder operation.`
+              );
+            }
+          }
+          element.children = Array.from(nextChildren);
 
           if (!element.isCollapsed) {
             const prevWeight = element.weight;
 
             let nextWeight = element.type === ElementTypeRoot ? 0 : 1;
 
-            children.forEach(childID => {
+            nextChildren.forEach(childID => {
               const child = ((this._idToElement.get(childID): any): Element);
               nextWeight += child.isCollapsed ? 1 : child.weight;
             });
diff --git a/src/devtools/views/Components/TreeContext.js b/src/devtools/views/Components/TreeContext.js
index 0be84a9e1d..f66ad3e46e 100644
--- a/src/devtools/views/Components/TreeContext.js
+++ b/src/devtools/views/Components/TreeContext.js
@@ -353,10 +353,6 @@ function reduceSearchState(store: Store, state: State, action: Action): State {
     }
   }
 
-  if (searchIndex !== prevSearchIndex) {
-    // The user intentionally navigated between search results
-    didRequestSearch = true;
-  }
   if (searchText !== prevSearchText) {
     const newSearchIndex = searchResults.indexOf(selectedElementID);
     if (newSearchIndex === -1) {
diff --git a/src/devtools/views/Profiler/CommitTreeBuilder.js b/src/devtools/views/Profiler/CommitTreeBuilder.js
index 0737dd8d6a..a91c7f0ab3 100644
--- a/src/devtools/views/Profiler/CommitTreeBuilder.js
+++ b/src/devtools/views/Profiler/CommitTreeBuilder.js
@@ -4,7 +4,7 @@ import {
   __DEBUG__,
   TREE_OPERATION_ADD,
   TREE_OPERATION_REMOVE,
-  TREE_OPERATION_RESET_CHILDREN,
+  TREE_OPERATION_REORDER_CHILDREN,
   TREE_OPERATION_UPDATE_TREE_BASE_DURATION,
 } from 'src/constants';
 import { utfDecodeString } from 'src/utils';
@@ -286,7 +286,7 @@ function updateTree(
         }
         break;
       }
-      case TREE_OPERATION_RESET_CHILDREN: {
+      case TREE_OPERATION_REORDER_CHILDREN: {
         const id = ((operations[i + 1]: any): number);
         const numChildren = ((operations[i + 2]: any): number);
         const children = ((operations.slice(
diff --git a/src/devtools/views/root.css b/src/devtools/views/root.css
index fd71c319ea..83dabea744 100644
--- a/src/devtools/views/root.css
+++ b/src/devtools/views/root.css
@@ -35,7 +35,7 @@
   --light-color-dimmest: #eff0f1;
   --light-color-expand-collapse-toggle: #777d88;
   --light-color-hover-background: #ebf1fb;
-  --light-color-inactive-background: #f1f1f1;
+  --light-color-inactive-background: #e5e5e5;
   --light-color-jsx-arrow-brackets: #333333;
   --light-color-jsx-arrow-brackets-inverted: rgba(255, 255, 255, 0.7);
   --light-color-modal-background: rgba(255, 255, 255, 0.75);