Loss of emails after changing storage/backup location

I’m trying to move the location of my backups, storage and logs from the c: drive to my e: (external) drive prior to using a new PC. The idea was to protect the emails on the external drive so I could simply plug it into the new PC (I’m going from Windows 10 to 11) create eM Client on the new PC, and then source my emails from that. I thought that would be straightforward.

However, it’s clearly not as simple as that.

When I yesterday changed the location to a folder in the e: drive (into which I’d copied the eM Client main folder, backup folder and storage folder from the c: drive), it seemed to revert to an older version of eM Client, and my sub folders in the side bar local folders were gone. The emails it initially showed were from 10 years ago, but newer ones then came in.

In accounts it showed two old email addresses I no longer use so I had to add my current one and delete those. It appeared that all the local folders’ emails had just been moved to the inbox. This I could get around by laboriously recreating the side folders, but I’ve then noticed that overnight I’ve lost emails that I had yesterday. I made a few new sub folders yesterday and put emails in them, but the sub folders have today now gone as have the emails I put in them.

I’ve tried restoring from backups, but each time I get an error message similar to this: Restore operation has failed. Contact eM Client and include the following information:

System.IO.FileNotFoundException: Could not find file ‘E:\eM Client 3\backup_202609212011.zip’.
File name: ‘E:\eM Client 3\backup_202609212011.zip’
at System.IO.FileInfo.get_Length()
at MailClient.DbBackup.FormBackup.Restore(String backupFile, CancellationToken cancellationToken)
at MailClient.DbBackup.FormBackup.Restore(CancellationToken cancellationToken)
at MailClient.DbBackup.FormBackup.<>c__DisplayClass27_0.<MainForm_Load>b__0(Object a, DoWorkEventArgs b)
at System.ComponentModel.BackgroundWorker.OnDoWork(DoWorkEventArgs e)
at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument)

It doesn’t seem to matter which backup date I pick prior to yesterday, none work.

Also, some of the settings I set up yesterday have reverted to what they were before I started.

Any suggestions would be welcome as I’m now afraid to change anything in case I make it worse.

Would uninstalling eM Client and reinstalling it help? Or would the uninstalling also delete the emails? Needless to say, I’ve been using a PC for many years, but I’m not good with the technical issues.

Thanks for your help.