Narrow popup doesn't allow editing attributes

Question

Sometimes the popup for entering attributes in a newly added feature or editing an existing feature through the edit widget is so narrow it is impossible to add values. Expanding the popup shows a white or blank space. Any ideas why this is occurring?

MikeOnzay · Accepted Answer

After working with ESRI support, we determined that the December update to ArcGIS Online probably caused this issue. That isn't really an answer because other web app builder apps that allow edits and existed prior to the December update may not have this issue. This was the first time I had created a WAB app that allowed editing.