IntelliJ IDEA didn't want to start this morning. Got the following error when trying to start it from a shell: Error occurred during initialization of VM Initial heap size set to a larger value than the maximum heap size What happened is that IntelliJ IDEA loaded the JVM Options from the new custom vmoptions file in the config directory. On Windows: %APPDATA%\Roaming\JetBrains\IntelliJIdea2020.1\idea64.exe.vmoptions On macOs: ~/Library/Application Support/JetBrains/IntelliJIdea2020.1/idea.vmoptions This file was not updated properly when I updated IntellIJ IDEA. It contained: -Xms4g -Xmx2048m Fixed the issue by editing this file: -Xms4g -Xmx4g Source: https://intellij-support.jetbrains.com/hc/en-us/community/posts/360004701620-idea-vmoptions-not-used-by-default