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

Below changes worked for me and hope the same works for you.

1. Change the version of Java from 11 to 8 in pom.xml file
   <java.version>1.8</java.version>

2. Go to, File -> Settings -> Build, Execution, Deployment -> Compiler -> Java Compiler
   Here, in Module column you can see your project listed and in Target bytecode version column, Java version for the project is already specified(mostly 11), change it to 8

3. Go to, File -> Project Structure -> Modules. Here, in Source tab, you can see Language level option, choose 8 - Lambdas, type annotations etc.. Finally, choose Apply and OK, you're good to go.

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 have recently 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 bytecode and 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.

1 of the 2 methods will fix the problem:

Method 1 (recommended)

Specify the Java version in your build file.

E.g., For Gradle, go to build.gradle file and specify the source and target compatability like mentioned in the docs and click on the refresh button in the Gradle tool window.

For example, to set source and target compatability to Java version 17:

java {
    sourceCompatibility = JavaVersion.VERSION_17
    targetCompatibility = JavaVersion.VERSION_17
}

Method 2

If building a project through a build system (Maven, Gradle etc..) via command-line 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.