Adobe Acrobat XI Pro and Big Sur

[yondrake]

After loading Big Sur, my pdf files that were created 7-10 days ago and earlier, failed to open.

The error message says that the file cannot be opened "because it is either not a supported file type or because the file has been damaged."

Has anyone else experienced this and if so, what was the remedy?

[Test Screen Name]

There is no chance at all of using old apps like Acrobat XI on Big Sur. but that doesn't explain how you got that message.