emClient will not start after manual copy to another computer

How can I proceed when dealing with unbootable computers?

Let’s say that I have a Windows 7 computer with the latest emClient on it and a GMail account set up. Everything works fine. Now, let’s say that this Windows 7 machine cannot boot anymore :
I have copied manually the entire “%appData%\eM Client” to a new user profile onto another computer running Windows 10 (with a different user name).
Now, if I start emClient on the new machine, DbRepair.exe runs instead of emClient and says (I translate the message from French, so, it may be different from official English strings) : “emClient has not been closed properly … Checking corrupted data … failed”
The details button gives that information :

System.IO.IOException: Process cannot access the file, because it is used by another process.
   to System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   to System.IO.__Error.WinIOError()
   to System.IO.File.InternalMove(String sourceFileName, String destFileName, Boolean checkHost)
   to DbRepair.CorruptionChecker.CheckCorruption(RepairOptions repairOptions, CancellationToken token)
   to DbRepair.CheckingProcess.Check(CancellationToken token)
databaseFile: accounts.dat

If I delete the account.dat file, I get the same thing for main.dat and then fro settings.dat.
After that, emClient starts jut like new and I cannot recover old emails.

This used to work with previous versions (I guess emClient 6 was OK with that but I am not sure if it was not emClient 5)
I hope I am clear enough with this issue.
Thanks for all the help you will be able to bring.

Hello, I have finally found the fix :
To make your emClient up and running again, you need to add a “dbcheckmagic” string value in the registry at “HKEY_CURRENT_USER\Software\eM Client” and set its value to “2” (without the quotes).
It worked like a charm after that.