Yes, it is possible to change the data source of a corrupt web map layer in ArcGIS Online. If a web map contains a corrupt web map layer, the layers do not appear when opening the web map in map viewer. This complicates any attempts to remove or edit the corrupt layer. In this case, ArcGIS Online Assistant can be used to update the URLs of the corrupt web map layer. To do so:
- Open ArcGIS Online Assistant.
- Log in with the ArcGIS Online account containing the corrupted web layer. All ArcGIS Online folders are listed on the left panel.
- Expand the folder containing the web map with the corrupted layer.
- Click the I want to… drop-down list on the top right corner.
- Select Update the URLs of Services in a Web Map.
- Select the web map with the corrupted layer. The name and data source of all the layers on the web map are displayed on the right panel.
- Update the corrupted map layer with the correct URL, and click Update.
- Log out of ArcGIS Online Assistant.
Note: ArcGIS Online Assistant is an unsupported product. Exercise caution when using this tool and test workflows before using it in production.