Ver. 4.7.6
I had difficult times to migrate to my new phone. Can't select document on the google drive which results in making new file for each phone I "synchronise". The only way I could at least move it into main phone was by copying template and sending it directly. I could do it with the data as well but then I would have no images. I ended to copy newly created data to older one. I don't have synchronisation from old to google sheets but at leasts I can use my new phone and have it synced to the google drive.

Someone said about this in google groups in mementodatabase too.
Title: Error sync with Google Sheets - 0 There is no key column in the Google Sheet table
https://groups.google.com/forum/#!topic/mementodatabase/zaJbdgzgwjM