Error: Java: invalid target release: 11 - IntelliJ IDEA

I've got the same issue as stated by Gryu.Same Intellij 2018 3.3

I was able to start my project by setting (like stated by Grigoriy)

File->Project Structure->Modules ->> Language level to 8 ( my maven project was set to 1.8 java)

AND

File -> Settings -> Build, Execution, Deployment -> Compiler -> Java Compiler -> 8 also there

I hope it would be useful

• I've got the same info messages and error message today, but I haverecently updated Idea -> 2018.3.3, built on January 9, 2019.

• To resolve this issue I've changed File->Project Structure->Modules ->>Language level to 10.

• And check File -> Settings -> Build, Execution,Deployment -> Compiler -> Java Compiler ->> Project bytecodeand Per-module bytecode versions. I have 11 there.

• Now I don't get these notifications and the error.

  It could be useful for someone like me, having the most recent Idea and getting the same error.

If building a project through a build system (Maven, Gradle etc..) works but IntelliJ show Invalid target release error, then do the following,

1. Close IntelliJ

2. Go to the directory of the project

3. Delete the .idea/ directory

4. Start IntelliJ with the project's directory

This will re-create the .idea/ directory and will no longer show the error.

NOTE: Any repository specific IntelliJ settings that you have added would be deleted when the .idea/ directory is deleted and they will be re-created with the defaults.