java: error: release version 17 not supported

Question

I recently updated to Intellij 2021.1. However, whenever I try to run my program, I get:

java: error: release version 17 not supported

I have tried snooping around for other answers, and have found none. It appears my sdk is version 16, if that helps.

Answer 1

This issue happened to me while upgrading to Java 17, I solved it by configuring the new SDK in project structure and invalidate the caches : File --> invalidate caches --> default selection and restart.

Answer 2

Your error is likely from IntelliJ attempting to call a Java 17 parser for compliance with Java 17 syntax (regardless of the SDK type) and there is no Java 17 JDK installed to perform the syntax checking with. You have 2 options.

Change 'Language Level' (Project Settings / Project in the Module Settings available from context window - right click - in the project window) to match your current SDK (ignoring possible language conflicts with more recent versions)

Download a Java 17 JDK to perform parsing with. That is in Platform Settings/SDKs in the same context menu, select '+', select 'Download JDK', then download and install a Java 17 version.