Is that in Gimp 2.10 File -> Open? Can't be, must be in Windows explorer. Have you tried File -> Open
I tend to use linux but even in Windows usually no problems opening Gimp 2.8 files in Gimp 2.10
The other way around is not always true however. Never seen that error. could a broken Gimp 2.10 or more probably a broken .xcf file.
Can you create /save/open .xcf new images in Gimp 2.10?
Not immediately obvious where that file is.
Does the other .xcf open?
I know these might not be available to the public but can you post one of the files, it might just be corrupted.
I tend to use linux but even in Windows usually no problems opening Gimp 2.8 files in Gimp 2.10
The other way around is not always true however. Never seen that error. could a broken Gimp 2.10 or more probably a broken .xcf file.
Can you create /save/open .xcf new images in Gimp 2.10?
Not immediately obvious where that file is.
Does the other .xcf open?
I know these might not be available to the public but can you post one of the files, it might just be corrupted.