diff --git a/src/ErrorHandler.tsx b/src/ErrorHandler.ts
similarity index 94%
rename from src/ErrorHandler.tsx
rename to src/ErrorHandler.ts
index c8b66687..53ad9064 100644
--- a/src/ErrorHandler.tsx
+++ b/src/ErrorHandler.ts
@@ -12,8 +12,7 @@ export interface ErrorCallback {
 }
 
 export class ErrorHandler {
-
-    static callbacks: ErrorCallback[] = [];
+    private static callbacks: ErrorCallback[] = [];
 
     public static registerCallbacks(callbacks: ErrorCallback[]): string {
         let guid = generateGUID();
diff --git a/src/ErrorInjector.tsx b/src/ErrorInjector.ts
similarity index 84%
rename from src/ErrorInjector.tsx
rename to src/ErrorInjector.ts
index c9a0610a..2cfc2bec 100644
--- a/src/ErrorInjector.tsx
+++ b/src/ErrorInjector.ts
@@ -4,14 +4,7 @@
  */
 import { AT } from './types/ActionTypes'
 
-export interface ErrorCallback {
-    actionType: AT;
-    callback: ((actionType: AT) => void);
-    guid?: string;
-}
-
 export class ErrorInjector {
-
     private static disabledActions: string[] = [];
     
     public static SetError(actionType: string, enabled: boolean) {
@@ -26,5 +19,4 @@ export class ErrorInjector {
     public static ShouldError(actionType: AT) {
         return (ErrorInjector.disabledActions.find(s => s == AT[AT[actionType]]) != null)
     }
-    
 }
\ No newline at end of file
diff --git a/src/actions/displayActions.ts b/src/actions/displayActions.ts
index 9ba91317..ff9f12d0 100644
--- a/src/actions/displayActions.ts
+++ b/src/actions/displayActions.ts
@@ -43,9 +43,9 @@ export const setErrorDisplay = (errorType: ErrorType, title: string, messages: s
     return {
         type: AT.SET_ERROR_DISPLAY,
         errorType,
-        title: title,
-        messages: messages,
-        actionType: actionType
+        title,
+        messages,
+        actionType
     }
 }
 
diff --git a/src/components/modals/AppCreator.tsx b/src/components/modals/AppCreator.tsx
index 52b3b2ba..e99d5d51 100644
--- a/src/components/modals/AppCreator.tsx
+++ b/src/components/modals/AppCreator.tsx
@@ -172,7 +172,8 @@ class AppCreator extends React.Component<Props, ComponentState> {
                 const appInput = this.getAppInput();
                 this.props.onSubmit(appInput, source)
             }
-            catch (error) {
+            catch (e) {
+                const error = e as Error
                 this.props.setErrorDisplay(ErrorType.Error, error.message, ["Invalid file contents"], AT.CREATE_APPLICATION_ASYNC)
             }
         }
diff --git a/src/components/modals/ErrorPanel.tsx b/src/components/modals/ErrorPanel.tsx
index 6b92b4fb..bd8c7549 100644
--- a/src/components/modals/ErrorPanel.tsx
+++ b/src/components/modals/ErrorPanel.tsx
@@ -10,7 +10,7 @@ import { Panel, PanelType, FontClassNames, DefaultButton } from 'office-ui-fabri
 import { clearErrorDisplay } from '../../actions/displayActions'
 import { State } from '../../types'
 import { ErrorHandler } from '../../ErrorHandler'
-import { injectIntl, InjectedIntlProps, InjectedIntl } from 'react-intl'
+import { injectIntl, InjectedIntlProps, InjectedIntl, FormattedMessage } from 'react-intl'
 import { AT } from '../../types/ActionTypes'
 import { FM } from '../../react-intl-messages'
 import { GetTip, TipType } from '../ToolTips'
@@ -88,7 +88,11 @@ class ErrorPanel extends React.Component<Props, {}> {
                     customWidth='600px'
                 >
                 <div className="cl-errorpanel" >
-                    {this.props.error.actionType && <div className={FontClassNames.large}>{this.props.error.actionType} Failed</div>}
+                    {this.props.error.actionType && <div className={FontClassNames.large}>
+                    <FormattedMessage
+                        id={this.props.error.actionType || FM.ERROR_ERROR}
+                        defaultMessage='Unknown '
+                    /> Failed</div>}
                     <div className={FontClassNames.medium}>{this.props.error.error}</div>
                     {this.props.error && this.props.error.messages.map((message: any) => { 
                             if (message == null)
diff --git a/src/react-intl-messages.ts b/src/react-intl-messages.ts
index 2f3643df..d969a032 100644
--- a/src/react-intl-messages.ts
+++ b/src/react-intl-messages.ts
@@ -1,3 +1,5 @@
+import { AT } from "./types";
+
 /**
  * Copyright (c) Microsoft Corporation. All rights reserved.  
  * Licensed under the MIT License.
@@ -488,8 +490,6 @@ export default {
         [FM.BUTTON_IMPORT]: 'Import',
         [FM.BUTTON_INFO]: 'Info',
 
-        // Custom Errors
-        [FM.CUSTOMERROR_NETWORK_ERROR]: 'Is your Bot running?',
 
         // Dashboard
         [FM.DASHBOARD_TITLE]: 'Overview',
@@ -849,6 +849,40 @@ export default {
         [FM.TRAINDIALOGMODAL_PRIMARYBUTTON_ARIADESCRIPTION]: 'Done',
         [FM.TRAINDIALOGMODAL_PRIMARYBUTTON_TEXT]: 'Done',
         [FM.TRAINDIALOGMODAL_CONFIRMDELETE_TITLE]: 'Are you sure you want to delete this Training Dialog?',
+        
+        // Error Messages
+        [FM.CUSTOMERROR_NETWORK_ERROR]: 'Is your Bot running?',
+        /** 
+         * This is kind of hack which re-uses redux action types as unit strings for localized error messages
+         * 
+         * It should probably be `errors.application.create` but we're using something like: `CREATE_APPLICATION_ASYNC`
+         */
+        [AT.CREATE_APPLICATION_ASYNC]: 'Creating application',
+        [AT.COPY_APPLICATION_ASYNC]: 'Copying application ',
+        [AT.CREATE_ENTITY_ASYNC]: 'Creating entity',
+        [AT.CREATE_ACTION_ASYNC]: 'Creating action',
+        [AT.CREATE_APP_TAG_ASYNC]: 'Creating application tag',
+        [AT.CREATE_CHAT_SESSION_ASYNC]: 'Creating chat session',
+        [AT.CREATE_TEACH_SESSION_ASYNC]: 'Creating teach session',
+        [AT.CREATE_TEACH_SESSION_FROMHISTORYASYNC]: 'Creating teach session from history',
+        [AT.CREATE_TEACH_SESSION_FROMUNDOASYNC]: 'Creating teach session from undo',
+        [AT.FETCH_HISTORY_ASYNC]: 'Fetching history',
+        [AT.FETCH_TUTORIALS_ASYNC]: 'Fetching tutorials',
+        [AT.FETCH_APPSOURCE_ASYNC]: 'Fetching application source',
+        [AT.FETCH_ENTITY_DELETE_VALIDATION_ASYNC]: 'Fetching entity deletion information',
+        [AT.FETCH_ENTITY_EDIT_VALIDATION_ASYNC]: 'Fetching entity edit information',
+        [AT.FETCH_ACTION_DELETE_VALIDATION_ASYNC]: 'Fetching action delete information',
+        [AT.FETCH_ACTION_EDIT_VALIDATION_ASYNC]: 'Fetching action edit information',
+        [AT.INIT_MEMORY_ASYNC]: 'Initializing memory',
+        [AT.RUN_EXTRACTOR_ASYNC]: 'Running extractor',
+        [AT.GET_SCORES_ASYNC]: 'Fetching scores',
+        [AT.RUN_SCORER_ASYNC]: 'Running scorer',
+        [AT.POST_SCORE_FEEDBACK_ASYNC]: 'Fetching score feedback',
+        [AT.EDIT_ENTITY_ASYNC]: 'Editing entity',
+        [AT.EDIT_ACTION_ASYNC]: 'Editing action',
+        [AT.EDIT_TRAINDIALOG_ASYNC]: 'Editing train dialog',
+        [AT.EDIT_APP_LIVE_TAG_ASYNC]: 'Editing application live tag',
+        [AT.EDIT_APP_EDITING_TAG_ASYNC]: 'Editing application editing tag',
     },
     'ko': {
         [FM.ABOUT_TITLE]: '약',
diff --git a/src/reducers/errorReducer.ts b/src/reducers/errorReducer.ts
index e81916b5..d59cc3f6 100644
--- a/src/reducers/errorReducer.ts
+++ b/src/reducers/errorReducer.ts
@@ -12,17 +12,27 @@ const initialState: ErrorState = {
     error: null,
     messages: null,
     actionType: AT.NO_OP
-};
+}
 
 const errorReducer: Reducer<ErrorState> = (state = initialState, action: ActionObject): ErrorState => {
     switch (action.type) {
         case AT.CLEAR_ERROR_DISPLAY:
-            return { ...initialState };
+            return { ...initialState }
         case AT.SET_ERROR_DISPLAY:
-            return { errorType: action.errorType, error: action.title, messages: action.messages, actionType: action.actionType }
+            return { 
+                errorType: action.errorType,
+                error: action.title,
+                messages: action.messages,
+                actionType: action.actionType
+            }
         case AT.FETCH_BOTINFO_FULFILLED:
             if (action.botInfo.validationErrors.length > 0) {
-                return { errorType: ErrorType.Error, error: `Configuration Error`, messages: action.botInfo.validationErrors, actionType: null }
+                return {
+                    errorType: ErrorType.Error,
+                    error: `Configuration Error`,
+                    messages: action.botInfo.validationErrors,
+                    actionType: null
+                }
             }
             return { ...state }
         default:
diff --git a/src/routes/Apps/App/Index.tsx b/src/routes/Apps/App/Index.tsx
index be5f261d..89e74184 100644
--- a/src/routes/Apps/App/Index.tsx
+++ b/src/routes/Apps/App/Index.tsx
@@ -16,7 +16,6 @@ import { AppBase, AppDefinition, ActionBase, ActionTypes, ApiAction, CardAction,
 import { injectIntl, InjectedIntlProps } from 'react-intl'
 import { FM } from '../../../react-intl-messages'
 import { State } from '../../../types';
-import { setErrorDisplay } from '../../../actions/displayActions';
 import { Icon } from 'office-ui-fabric-react/lib/Icon'
 import Entities from './Entities'
 import TrainDialogs from './TrainDialogs'
@@ -245,7 +244,6 @@ class Index extends React.Component<Props, ComponentState> {
 }
 const mapDispatchToProps = (dispatch: any) => {
     return bindActionCreators({
-        setErrorDisplay,
         setCurrentApp: actions.display.setCurrentApp,
         createApplicationThunkAsync: actions.create.createApplicationThunkAsync,
         fetchAppSource: actions.fetch.fetchAppSourceThunkAsync,
diff --git a/src/routes/Apps/App/LogDialogs.tsx b/src/routes/Apps/App/LogDialogs.tsx
index 86b16c67..a89b880c 100644
--- a/src/routes/Apps/App/LogDialogs.tsx
+++ b/src/routes/Apps/App/LogDialogs.tsx
@@ -17,7 +17,6 @@ import {
 } from '../../../actions/createActions'
 import { deleteLogDialogThunkAsync } from '../../../actions/deleteActions';
 import { fetchAllLogDialogsAsync, fetchHistoryThunkAsync } from '../../../actions/fetchActions';
-import { setErrorDisplay } from '../../../actions/displayActions';
 import { injectIntl, InjectedIntl, InjectedIntlProps, FormattedMessage } from 'react-intl'
 import { FM } from '../../../react-intl-messages'
 import { Activity } from 'botframework-directlinejs';
@@ -599,7 +598,7 @@ class LogDialogs extends React.Component<Props, ComponentState> {
                     teach={this.props.teachSessions.current}
                     dialogMode={this.props.teachSessions.mode}
                     isOpen={this.state.isTeachDialogModalOpen}
-                    onClose={this.onCloseTeachSession}
+                    onClose={this.onCloseTeachSession} 
                     onUndo={(popRound) => this.onUndoTeachStep(popRound)}
                     history={this.state.isTeachDialogModalOpen ? this.state.history : null}
                     lastAction={this.state.lastAction}
@@ -618,7 +617,6 @@ const mapDispatchToProps = (dispatch: any) => {
         deleteLogDialogThunkAsync,
         fetchAllLogDialogsAsync,
         fetchHistoryThunkAsync,
-        setErrorDisplay
     }, dispatch)
 }
 const mapStateToProps = (state: State) => {
diff --git a/src/routes/Apps/App/TrainDialogs.tsx b/src/routes/Apps/App/TrainDialogs.tsx
index 27c43f66..381c3e2c 100644
--- a/src/routes/Apps/App/TrainDialogs.tsx
+++ b/src/routes/Apps/App/TrainDialogs.tsx
@@ -21,7 +21,6 @@ import { deleteTrainDialogThunkAsync, deleteMemoryThunkAsync } from '../../../ac
 import { editTrainDialogThunkAsync } from '../../../actions/updateActions';
 import { injectIntl, InjectedIntl, InjectedIntlProps, FormattedMessage } from 'react-intl'
 import { FM } from '../../../react-intl-messages'
-import { setErrorDisplay } from '../../../actions/displayActions';
 import { Activity } from 'botframework-directlinejs';
 import { autobind } from 'office-ui-fabric-react/lib/Utilities';
 import { getDefaultEntityMap } from '../../../util';
@@ -750,7 +749,6 @@ const mapDispatchToProps = (dispatch: any) => {
         createTeachSessionFromUndoThunkAsync,
         createTeachSessionFromHistoryThunkAsync,
         editTrainDialogThunkAsync,
-        setErrorDisplay
     }, dispatch)
 }
 const mapStateToProps = (state: State) => {
diff --git a/src/services/poller.test.ts b/src/services/poller.test.ts
index 56b70a9c..798307c0 100644
--- a/src/services/poller.test.ts
+++ b/src/services/poller.test.ts
@@ -26,7 +26,7 @@ describe('Poller', () => {
         await poller1.addPoll(pollConfig)
 
         expect(onExpiredMock.mock.calls.length).toBe(1)
-        expect(onUpdateMock.mock.calls.length).toBeGreaterThan(3)
+        expect(onUpdateMock.mock.calls.length).toBeGreaterThanOrEqual(3)
     }) 
 
     test('poll should invoke request, isResolved, and onUpdate for each interval', async () => {
@@ -143,6 +143,6 @@ describe('Poller', () => {
         await p1 // Will still resolve after 400 expiration
         const after = new Date().getTime()
         
-        expect(after - now).toBeGreaterThan(400)
+        expect(after - now).toBeGreaterThanOrEqual(400)
     })
 })
\ No newline at end of file