Problem Loading App: The App interface could not be loaded

[michalikm]

Hello all!

I've seen a few posts regarding this issue that show likely causes, but don't address how to troubleshoot. In the process of updating around 25 applications in designer and uploading them to the gallery, one of the apps is giving us the "Problem Loading App: The App interface could not be loaded" error message in the gallery.
For context, this specific app had not been updated in years (I think 2016), and we did not have a version saved locally, so the version we made edits to (in designer) had to be downloaded from our server (We'll call this Version 1). Version 1 works fine. The edited version (Version 2) is giving us the error message. None of the other two dozen applications we made updates to gave us this issue, so I don't think it's a version discrepancy issue...

That said, the two most common causes we've seen on the discussion boards relate to Designer/Server version discrepancies, and something about inaccurate credentials.
1. How would I validate the version used on the server (I know my designer version is 2020.4.5.12471)?
2. Is it possible there are tools within the workflow that are incompatible with the version we are using (since the app was last updated a while ago), and how would we look for this? There were no errors in designer when making updates, which I've seen before when downloading workflows from discussion boards.
3. Is the credential issue something that can be validated? When I look on the server under credentials, it looks as though none are setup.

4. Any other thoughts on causes and how to troubleshoot without rebuilding the workflow from scratch?

Thank you in advance for your help!!

[KGT]

One of the difficulties that you may come across is that you are using old versions that are out of support. This can make it a lot harder to find the correct troubleshooting steps. Without knowing what Interface tools are in the workflow, it's hard to tell what the issue is. Any chance you can post a screenshot at least, so we can get an idea of the tools used?

Just checking, this workflow is designed for Gallery webpage access, not API access, right? I say that as something built in 2016 for Gallery may have been designed specifically for API access and so the naming conventions etc may be different. At that time, Gallery API was new and so there were many different techniques to get the most out of it. This is not a showstopper, just may help to advise what to check.

1. You can check the server version through Gallery. There should be an about page or similar. 
2. Possibly, not easy to check as it's not meant to happen. Most common is Python based connectors being configured to a version on install and that version changing, but if the workflow was built in 2016, then that won't be the case.
3. Does the workflow need credentials? Or are you talking about the Gallery credentials? If the workflow doesn't need credentials, then this may be a misnomer. However, make sure that it's not gallery credentials based on it being in a different studio and not having permissions for that.
4. Versions could be an issue, but what interface tools are being used? And do they have assigned names under the tool configuration??

[michalikm]

Thank you for the information @KGT !

I've included two images, the first (though a bit zoomed out) showing the interface tools used within the app. The second showing what version information is showing within the gallery. I unfortunately don't have a lot of control over which version we are able to run currently. The app was designed for webpage access not API access.

The only changes made to the app between the working version and the newly published version that are prompting the error message are to text found within a Text Input tool. The interface tools contained within the app are Text Boxes, Numeric Up Down, Condition tools, File Browse, Radio Buttons, Drop Down tools, and Action Tools.

I'm not exactly sure how to check if they have assigned names under the tool configurations, though when I look at Configuration for each tool, I don't see anything that looks odd. They each start with "Enter the text or question to be displayed:" and each is filled in appropriately. The workflow itself does not require credentials, I just saw that mentioned somewhere on another post. No python within the workflow either, it's a pretty basic workflow, no macros, just In/Out, Preparation, Join, Transform, Reporting, and a few Spatial tools.

Any further help you could provide would be greatly appreciated!

[apathetichell]

if you download the version from server--- don't save it. open it in notepad ---> you should be able to see what version server is running. two questions 1) what version of Alteryx is your desktop running? (I presume in the 2020 series) 2) another reason that you could see this issue is that Alteryx is looking for an input file for an interface tool which it does not have access to. I don't see why that would change in versions ---> unless you changed one of the settings on an interface tool between versions ---> or you are not loading a static file connected to an interface tool in your workfload dependencies when you redeploy it as version 2.

[KGT · Accepted solution]

I can't see anything in that image that stands out, but if the problem is still occurring then try removing/replacing some of the interface tools (a container at a time) and publish to your studio to test. As above, test the ones that require external files first.

You can also use the interface designer to test it, and see if there's anything that looks funky there. Another option is also to try it on the designer on the server. This one may just take some extra care, but I expect it'll be something relatively simple when you find it.

[michalikm]

Thank you both @KGT @apathetichell ! I was not able to correct the issue, but was able to isolate the interface tool that was preventing the app from working on gallery and remove/replace..