Showing results for 
Search instead for 
Did you mean: 
Regular Visitor

Power App Editor (Web and Windows) Crashing when Opening a Power Apps file for editing

I have been working on an app that can not be opened with PowerApps Windows (on Windows 10). At this point, when I open the file, it shows the message that Unsaved Changes are Detected.


I can click either Recover or Discard and then, if I attempt to open the app to edit, PA crashes with no error messages.


If I open the app file in the Web version, I get the following message Immediately after the app is opened and the first screen is displayed for editing. (This message is overlayed on the editing screen).


WebAuthoring abnormal termination.
Client date/time: 2017-07-19T20:00:32.278Z
Version: 2.0.663
Session ID: 8d5c01fe-7f0f-4cf5-4b58-4455d85c735c
description: {"error":{"isTrusted":true,"detail":{"exception":{}},"message":"Uncaught TypeError: Cannot read property 'controlContexts' of null","filename":"","lineno":2... TypeError: Cannot read property 'controlContexts' of null","setPromise":"[function]","exception":{}}
stack: null
errorNumber: 0
errorMessage: Uncaught TypeError: Cannot read property 'controlContexts' of null


I have uninstalled and re-installed the PowerApp studio from the Windows store with no changes. At this point, I am unsure what to do -- I have a lot of time invested in the app, it was running recently so whatever "last change" I made, caused it to crash. How can I recover this app?




Accepted Solutions

We did figure out FBGLUCK's problem and it was not related to Forms/Galleries at all. It was related to the use of Reset in a formula on a screen's OnStart property.

View solution in original post

Power Apps
Power Apps

This appears to be a bug caused by having a Form inside of a Gallery. Suggest using the Portal to go back to an earlier version of your app, and avoid adding a Form inside a Gallery.

Thanks for the quick reply!


When you say "Portal" can you clarify what you mean by this term? This app is being developed and tested on a Windows 10 system and is opened from a file named Attendance_Entry.msapp. I am not sure if there is an "earlier version" somewhere or where I would go to get one.


Also, I am using neither forms or galleries in the app. The app is simply three screens with text fields, buttons and the actions that go with them.





Not applicable

The same thing happens to me often. It seems to happen to me multiple times per week.... The only way to resolve it is by restoring a previous save. In my opinion this should be one of the top priorities for the PowerApps team to fix.

Sorry, what we call the Portal you see at - go to Apps and you will see each and every version you have saved.


However if this is not forms/gallery related then my diagnosis is likely wrong.

I don't see the app in the portal (probably because I did all the development and testing using the Windows version of Powerapps).


The first time I opened the portal and tried to open the msapp file was when I got the error message ... so... I am guessing tht there are no "previous versions" saved anywhere (unless the Windows version of the editor saves them somewhere).


The only version that I have is in my local file system and I believe that everytime I do a save from the Windows editor, it gets overwritten.


Why do I think that this isn't going to turn out well 🙂




Please PM me so we can figure this one out.

Hi @AndyPennell,


Don't get me wrong, but your diagnosis is wrong... As I mentioned you in another thread, I've the same problem and I don't use a form inside a gallery.


Best regards,

Jorge Moreira

Not applicable

I have this problem sometimes and I do not use forms inside of galleries. I have this problem when I use complex or unusual formulas. Some small part of the formula confuses PowerApps. Still the only way to fix it is to rollback your app to earlier versions until it works.

The problem is that in v661 there was no problem, but now, in v663 I have this error...

Helpful resources

Power Apps News & Annoucements carousel

Power Apps News & Announcements

Keep up to date with current events and community announcements in the Power Apps community.

Microsoft 365 Conference – December 6-8, 2022

Microsoft 365 Conference – December 6-8, 2022

Join us in Las Vegas to experience community, incredible learning opportunities, and connections that will help grow skills, know-how, and more.

Power Apps Community Blog Carousel

Power Apps Community Blog

Check out the latest Community Blog from the community!

Top Solution Authors
Top Kudoed Authors
Users online (2,853)