Why Windows 11 version 24H2 can't open .adi file?

In Windows 11 version 23H2 I could open .adi files created by a backup program by simply double-clicking the file in Windows Explorer without calling the backup program. It simply displayed the file content in the Windows Explorer. 

After the upgrade to the 24H2 version, Windows cannot open the file. It simply does nothing. The file is OK and opens fine with the backup program.
Any idea what's going on?