Help me please why this happen..
Don't post screenshots of text! That is very unhelpful.
Please do this:
- File > Preferences > Show verbose output during: > compilation (check) > OK
- Sketch > Verify/Compile
- After the compilation fails you'll see a button on the right side of the orange bar "Copy error messages". Click that button.
- Paste the error messages in a reply here USING CODE TAGS (</> button on the toolbar).