(No pun intended, but...

However, when I try to backup them to a new location I get this error:
"Failed to copy from Source : Unable to compress file: The file could not be saved in the archive".
But it worked fine with an earlier version of SyncBackPro, about a year ago.
I tried to manually change the timestamp to January 1 1900 (using the SKTimeStamp plugin for Windows Explorer) and then it works fine,
but if I change it back to December 31 1899 the error comes back.
I'm running SyncBackPro v8.5.26.0 (64-bit) on Windows 10.
It's a "Fast Backup" profile with "Compress the files on Target into a Zip file" and "Copy file creation date & times" enabled.
Thanks for any help,
Mikael