- Fix compiler error.
- Make sure you have "using UnityEngine;" in your namespace.
- make sure you have the same names for classname and filename
I assume your file has a big "I" instead of a small "L" or a special character.
to check it paste both, the Filename here and then the Class name here:
Compare for special characters. (red)
i != í for example
You might have accidently pushed ´ or ` something before pushing the i button, resulting in a different class name than file name.
To make it 100% sure copy and paste the classname to the filename.