Microsoft is blocking Windows 11 upgrades if customers use applications that create registry keys using some non-ASCII characters.
As the company explains, on impacted systems such apps might be unable to open and could also cause other issues or errors in Windows 11, version 21H2 including blue screens.
“Compatibility issues have been found between apps using some non-ASCII characters in their registry keys or subkeys and Windows 11,” Microsoft explains.
“Affected apps might be unable to open and might cause other issues or errors in Windows, including the possibility of receiving an error with a blue screen.”
To make things even worse, in some cases, registry keys with non-ASCII characters might also be irreparable.