Crash on Startup (Gradle Log)

C:\Pylo\MCreator183\forge\build\sources\main\java\mod\mcreator\mario_mod.java:66: error: cannot find symbol
        elements.add(new mcreator_sky(this));
                         ^
  symbol:   class mcreator_sky
  location: class mario_mod
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
1 error

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 1s