Experience Builder won't save after adding custom widget

Question

I'm currently trying to migrate some WAB apps over to Experience Builder, and all of these apps have some custom widgets in them. However, if I add the custom widgets that I'm working on to the app layout, I can no longer save any changes made to the app. I don't get an error message or anything, the save button just shows the three dots loading indefinitely, and if I refresh the webpage any changes made since my last save are gone.

Has anybody else had this kind of issue? I searched these forums but couldn't find anything on this. I'm currently using ArcGIS Experience Builder (Developer Edition) 1.12 running on Windows 10 Enterprise 64-bit (10.0, Build 19044).

ruikaitang_brampton · Answer

No, I've been rewriting. The only thing being ported over is the HTML for the frontend UI which has been converted to JSX, I haven't gotten to rewriting the 3.x ArcGIS JS API code for 4.x yet. I'll take a look at the JSON formatting though.

Jeff.Thompson@arlingtontx.gov_arlingtontx · Answer

Are you trying to directly drop Web App Builder widgets into Experience Builder? They are not compatible.

Assuming you have built new Experience Builder widgets, check your config.json files very carefully to make sure they are properly formatted, especially trailing commas. I have seen a lot of weird issues that I have traced back to json formatting.

ruikaitang_brampton · Answer

Currently I haven't actually ported over any of the backend geoprocessing tools, it's strictly frontend UI in JSX for the React framework that was converted from the HTML of the old WAB widget. Currently there aren't any calls to Jimu libraries in the widget, but this information is good to know for when I do start migrating backend functionality. Is there anything in there currently that could be potentially causing this problem?