Transfer between computers

Having used EMClient on computer #1 (Windows 7) for some years, I want to transfer all data to computer #2 (Windows 10) - as #1 is now too unreliable. EMClient is installed on both computers, is activated and seems to be running correctly. 
I have produced a backup (File>Backup) of all data from #1 to a zip file (as I do on a regular basis) and have transferred this file to the folder (as given by Tools>Settings>General>Backup) on #2. When attempting to restore from this file I then get the error message “Selected folder does not contain any backup files. Please select another location”.
I then created a backup file from #2, which produces a tiny file as there are now emails. Attempting to Restore from this 2nd backup (same computer, same folder, same file) produces exactly the same error message.
Any ideas?

Looks like it is not recognizing the backup zip file for some reason.

You can manually extract the zip file to C:\Users_[username]_\AppData\Roaming\eM Client. 

Thanks. That works well.