Solutions for ‘Intellij IDEA Java classes not auto compiling on save’ February 13, 2021 admin Try some options below: 1. mvn idea:idea 2. cd yourporject/path, rm *.iml *.ipr *.iws, the reopen idea, maven build again 3. Alt+shift+A, Type:Registry choose compiler.automake.allow.when.app.running to check