The following error is displayed and cannot be deleted.
Failed to delete model-driven app. Principal user (Id=7af90a22-1d72-ea11-a811-000d3a5540ae, type=8, roleCount=2, privilegeCount=616, accessMode=0), is missing prvDeleteAppModule privilege (Id=af523536-9728-4164-9a2d-fbaf85a679d2) on OTC=9006 for entity 'appmodule'. context.Caller=7af90a22-1d72-ea11-a811-000d3a5540ae
It seems that the Action Approval Model of the solution is related, but I don't know what to do after this.
You cannot directly edit the components within a managed solution. If the managed properties for solution components are set to allow customization, you can edit them from another unmanaged solution.