Q: Continuously getting the java: invalid source release: 1.9 error when compiling I have attempted to fix this problem using the various forums on this site, but nothing has helped. I tried similar techniques as used to fix other people's 1.8 errors, but nothing has worked. I have my java class file under my source folder and no imports, I just simply want a basic output message to make sure intelliJ is working as it should. Can anyone offer any advice?

A: Here change the language level to 1.8 or lesser. This changes the target release version.

Go to file -> settings -> Build Execution and Deployment -> Java -> Compiler

Here change the language level to 1.8 or lesser. This changes the source release version.

File -> Project Structure -> Module Settings -> Tab: Source: Language
  Level

and also here,

File -> Project Structure -> Project(In left pane) -> Project language level


A: Just in case anyone stumbles onto the same problem and the above answer doesn't solve it, my issue was resolved doing the following (I was using Gradle):


*

*Open the your-project-name.ipr file.

*Verify the following line:


<bytecodeTargetLevel target="1.xx" />
Mine was set to 1.10. I changed it to 1.08 (which my project SDK was set to) and the problem was solved. 
