Hello. I've also never had to deal with this error.
I did some searches, and I cant find any feedback on "these layer files are not compatible with new version of photoshop". Are you sure this is how the error reads? It actually reads "layers" or "layer files"?
Could it have read, "Could not complete your request because the file is not compatible with this version of Photoshop"? Or, "PSD file not compatible with this version of Photoshop"?
A screenshot of the error would be great if possible.
I have read that you can try accessing a "non compatible" PSD file using another Adobe program and convert them into new PSD files. Do you have any other Adobe programs?
Let us know!