“Could not find the main class: XX. Program will exit.”

Question

I have managed to run my jar file with a command prompt, but its always giving me a reponse of

Could not find the main class: XX. Program will exit.

Answer 1

I had the same error. The problem was that Windows 10 suddenly decided to set my workspace folder to read-only.

After removing the read-only checkmark in the folder's options, the problem was solved.