That may mean that MobileSheets does not currently have permissions granted to access your storage. You need to check two things:
1) Go to your tablet settings->Apps
2) Tap the three dots at the top right, then Special Access->All files access
3) Toggle the "all files access" permission on for MobileSheets
4) Now start MobileSheets and see if your files load properly. You may also need to go back to your tablet settings->Apps->MobileSheets->Permissions and verify that the "Storage" permission has been turned on.
Google can revoke granted permissions under certain circumstances (such as not using the app for a while), and the app would normally prompt the user to grant the permission again, but the "All files access" one is handled a little differently, as it's technically optional and I didn't want to constantly badger users that left it off.
I just want to have you check that in case it's related.
Mike
1) Go to your tablet settings->Apps
2) Tap the three dots at the top right, then Special Access->All files access
3) Toggle the "all files access" permission on for MobileSheets
4) Now start MobileSheets and see if your files load properly. You may also need to go back to your tablet settings->Apps->MobileSheets->Permissions and verify that the "Storage" permission has been turned on.
Google can revoke granted permissions under certain circumstances (such as not using the app for a while), and the app would normally prompt the user to grant the permission again, but the "All files access" one is handled a little differently, as it's technically optional and I didn't want to constantly badger users that left it off.
I just want to have you check that in case it's related.
Mike