The last time I used Scrivener was in Nov 2014. This week I installed the latest version on a new computer and tried opening up an old Nov '14 backup from my Google Drive. I got a message saying that the Scrivener can’t open the older file type and that it would have to convert the project to a new file type. I completed this process and opened up the converted project. So far, everything seems to be as it was. Are there any changes that I should worry about?
But once the project converts successfully, you should be off and running.
HOWEVER, we do not recommend using Google Drive to store live Scrivener projects. It appears to have trouble keeping up with Scrivener’s frequent saves, which can lead to data loss and project corruption.
A different member here:
Suppose I don’t want to keep the old (data) version (not the old software, of course). Which files are safe to delete? They all seem to have the same names!