Regression / Change in 3.20021.29 to 3.20022.19 related to the Experimental feature Formula-level error management

[BrianHFASPS]

Today I ran into issues it appears due to changes in 3.20021.29 to 3.20022.19 related to the Experimental feature Formula-level error management. I made two other posts about it https://powerusers.microsoft.com/t5/Building-Power-Apps/App-broke-in-last-24-hours-Published-version... and https://powerusers.microsoft.com/t5/Building-Power-Apps/Converting-null-Time-from-SQL-results-in-not.... My code stopped dealing with null the way it did a day ago. I wanted to post with a more appropriate title in case others ran into same issue. Thanks to @PaulD1 for the assist in pointing this out.

I am happy to share any details of app or processing to help figure this out.

[PaulD1]

Thanks @BrianHFASPS 

Can you confirm whether this broke your production applications?

I have had two occasions where production Apps have stopped working due to platform changes - i.e. they had been working fine for weeks and worked on a Friday afternoon but were broken on the Monday morning despite no re-publishing or other modifications on our side.

We are having to decide what advice to give to customers with regards to Apps implemented in PowerApps - should we be able to assume that an App, if untouched (i.e. no modification / re-publishing) will continue working indefinitely?

Retesting a PowerApp is no small undertaking (lack of automation, many scenarios to consider) and if the expectation is that we need to do that every few months (schedule?) to avoid outages, that is simply not going to be sustainable.

[v-xida-msft]

Hi @BrianHFASPS ,

Thanks for your feedback. Based on the issue that you mentioned, it seems to be related to PowerApps updates.

If you want to get further help in this issue, please consider submit an assisted support ticket through the following link:

https://powerapps.microsoft.com/en-us/support/pro

Best regards,

[BrianHFASPS]

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@v-xida-msft wrote:

Thanks for your feedback. Based on the issue that you mentioned, it seems to be related to PowerApps updates.

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I have done so thanks.

[BrianHFASPS]

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@PaulD1 wrote:

Can you confirm whether this broke your production applications?

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This is a tricky answer. It might unfortunately be not yet? In this case the published app was working but I was in active development of additional features. The act of publishing an update with revised back end platform was breaking it. However if I just had a stable app that I left alone it could have potentially kept working for some indeterminate time. Did the update break the published app, technically no. Did it break it in that I couldn't modify the app, yes. The app was taking advantage of experimental features so maybe that is my fault, but I think it is a regression for sure.

[PaulD1]

Thanks @BrianHFASPS 

I'm trying to figure out the extent to which I should be trusting PowerApps for any kind of critical work. I've experienced two occasions where my production apps were broken by updates to the platform (i.e. no republishing on new versions) and I want to hope that these were onetwo-offs.

That said, I'm also concerned about stability/quality of version updates when republishing - seems this latest release not only has bugs relating to Formula-level error management you have described on this thread, but I'm also seeing posts stating that the way AddColumns and ShowColumns work together has changed and is breaking apps when re-published (requiring re-work and re-test).

I am often asked to make small tweaks and amendments to existing apps, but if the version has been up-revved since the App was last published, I really should complete full end-to-end testing taking into account all sorts of edge cases to be sure new bugs have not been introduced to the App. This drastically changes the value proposition of PowerApps, quicker and cheaper to create than with traditional dev tools but massively expensive to maintain and much more risky to operate (tests will never catch every possible bug).

[BrianHFASPS]

Most of my issues seem to co-mingle null and AddColumns. I wonder if I am hitting both. Didn't realize there were AddColumns issues happening as well. I have been engaged by an engineer in PowerApps to try and fix the issues. Hopefully some progress soon.

It is definitely different than C# programs or something. The underlying language definition changes rarely and the complier also less often than something like the power platform. It is definitely a risk when the player / platform are rapidly evolving.

[PaulD1]

As I understand the ShowColumns/AddColumns issue it relates to using ShowColumns to exclude a column and then AddColumns to add a new column of the same name. Apparently this used to work but now doesn't. Of course, there may be other issues as well that you are hitting.

Fortunately in the cases I saw reported, the App checker throws this up as a bug. What really shakes my confidence is when a change 'breaks' the App, but it does not show up in the App Checker (e.g. changes to Explicit columns selection meaning that columns that used to be retrieved are no longer fetched, changes that result in If statements giving different results for the same set of inputs) that leave the App apparently running without bugs, but end up recording the wrong data (or no data) in your database.