Map layer loads and then doesn't, then it does!!! Enterprise 11.1 Portal map service

[John_Tyll]

Hi, We are running Enterprise 11.1 and EXB Dev 1.14.  The example errors I have are from Edge Dev tools console. We have a handful of EXB apps built the same way different services that run fine. This EXB will load all layers fine usually the first few times and then we get 3 layers (or a combination of 1,2, or all 3 of about a dozen layers) that fail to load. And if you are lucky and you check again they sometimes load while using the app.  Anyone understand why this may be happening?  See the image attached. Notice on the right in the dev tools window the 3 failed to load layers and then further down the message recreate mapbaseview because layers that previously failed to load blah blah...  and you can see in the EXB Map Layers pane, indeed the layers are now there. This is frustrating because it appears to be random when the layer(s) will fail to load and I don't see anything special about these layers compared to others we published.  

Looking forward to hearing your feedback!

Thanks!

John

[simoxu]

Do you have the same issue when loading the web map in ArcGIS Portal Map Viewer?

If the webmap loads fine in the map viewer, it means something is wrong with your web application.

The screenshot shows you are loading the webmap in a custom web application, some of the code may be causing the issue.  for example, some libraries may fail to load before the application is initialized, and it's kind of random. Please see if the following post helps.

Solved: Re: Cannot read property 'toLowerCase' of null - Esri Community

[John_Tyll]

Thanks for the reply simoxu.  The webmap does not seem have to have any issue in the Enterprise 11.1 Portal map viewer. When we use it in the Enterprise 11.1 Experience Builder and the Developer 11.4 Experience Builder, which we are currently using, we have this problem. We have other Experience Builder Apps (built by the same person, with services they published the same way) that we do not have any issues with. I am struggling to find what is different.  

[simoxu]

Ok, that means it's not an ArcGIS Enterprise platform issue, it's an application issue.

Try to configure an EXB web app with the out-of-box widgets, I mean without any customization and see if it works. if it works in the map viewer, it should work in this case.

If you can prove it's the application issue caused by the customization, you'll have to get the developer to fix it. 

Please keep this in mind, when you upgrade your ArcGIS Enterprise, those customized code won't be upgraded automatically, you'll need the developer to upgrade the code accordingly.

[John_Tyll]

UPDATE: Changing the impacted services from map services to feature services worked for a few of the troubled layers, kind of. WHY?  Unknown.  FIXED: Upgraded to 11.3 changed back to using map services and no problems with any of the layers.