Experience Cards Widget failing in custom Mobile and Tablet view

[AnneReynolds]

If an Experience application uses the Cards or List Widget, and you customize the mobile or tablet views, the published mobile and tablet views produce this error:

Cannot read properties of undefined (reading 'layout_23')

but the Desktop view works fine.  Using Auto on Tablet and mobile view configuration is not an option.

[NicoleJohnson · Accepted solution]

@AnneReynolds, this is kind of out of left field, but is the header or footer of your experience set to auto? If so, try switching it to custom and seeing if the error resolves. I had the exact same issue recently and initially thought the issue was caused by something else, but it turns out there's a bug that will affect tablet and mobile views when headers/footers are set to auto (edit: and the new accessible labels are turned on). 

[AnneReynolds]

If by "out of left field" you mean removing headers and footers will completely solve your issue, then YES it is!!!

I just removed the footer to test, but how do you remove AUTO setting on Headers and Footers?

[NicoleJohnson]

@AnneReynoldsin the tablet and mobile device views, you'll see an auto/custom toggle for each content area (header, body, and footer--pictured here are the toggles for the header and body). This is for sure a bug by the way, and it's in the product plan to address it.

I edited my post above, but IIRC the actual culprit is the new accessible labels setting. I haven't tried just turning that off, but I bet you could do that and the issue would resolve (as an alternative to setting headers etc. to custom).

[AnneReynolds]

I appreciate you Nicole!  We are doing a BETA launch this weekend and were scrambling for a mobile solution.  You really got us out of a bind!!!  Any idea of the timing of the bug?  Accessibility is important in the long run (but can be left out for this weekend).

[NicoleJohnson]

Here's the bug: BUG-000181503 for ArcGIS Experience Builder

"In product plan" means they intend to fix the issue within the next release or two (ArcGIS Online is updated four times a year). Since it was found in October 2025, hopefully soon!

[AnneReynolds]

If an Experience application uses the Cards or List Widget, and you customize the mobile or tablet views, the published tablet view produce this error:

Cannot read properties of undefined (reading 'layout_23')

When viewed on a phone it produces this error:

undefined is not an object (evaluating 'r|e|')

but the Desktop view works fine.  Using Auto on Tablet and mobile view configuration is not an option.

also accidentally posted on Enterprise Board