Hi,
I reinstalled the app from the playstore last night to try the legacy mode option and record the error message. The install was different this time and the sequence of access approval for folders was different. Sure enough, it is still working today so I'm pleased to say that I don't have the error message!
I didn't have the setting for legacy mode... couldn't find it anywhere.
Fingers crossed something has changed and it will continue to work.
Thanks.