After the last Win Update (from Win 11 21H1 to 22H1), I can not start Biab when doubleclicking on Biab-project datas directly. The program does not start, but there is a message:

(Translation)
"The specified device, path, or file cannot be accessed. You may not have sufficient permissions to access the item."

How can I make access possible again? (By the way, it is still possible to start biab at first and then load the projects)

sounds like you've lost the link between BIAB files and the BIAB program. right click on a BIAB file, choose 'open with' and BIAB should be there as there as the associated program.

east enough to try in the first instance

Try this:

Use Windows Explorer, navigate to the C:\bb\ folder (presuming your BiaB is installed on C: drive) and search for the file bbw64.exe. (presuming that your setup shows file extensions, otherwise look for a file type with than name of type: Application and size around 56Mb - see third image).

1: Right-click on the file and select
2: Send To
3: Desktop (create shortcut)

Then double-click on the newly created shortcut on the desktop.

"sounds like you've lost the link between BIAB files and the BIAB program. right click on a BIAB file, choose 'open with' and BIAB should be there as there as the associated program."

Hello Bob Calver, this was the problem. Now, it works again!

Thanks @all for your help!