You need to resolve the issue with THIISSS.
You need to resolve the issue with THIISSS.
They aren't suggesting you actually type .xyz. Just swap it for the file extension your program expects, like .exe. It looks clear from what you wrote.
these are files that run directly, but they don’t function as expected.
Set up Tune Up Utilities, it offers a feature to resolve issues with icons and window displays, effectively addressing most problems in one step.