So, theres no much more to say, was running the client just fine ( With the IDE ), It didn't throw any error.
But i had to compile to test a feature, i copied the file, deleted the build folder and when i tried to run the client, it throws this error:
Exception in thread "main" java.io.UncheckedIOException: java.io.IOException: Invalid paths argument, contained no existing paths: [\mod\bin\default]
I think deleting the build folder may have caused the problem, sorry if this is obvious but im new to the modding world even if i knew a bit of java before.
And last my apollogies if theres any Spelling/Grammar mistake, im not english native.