I have a plugin that depends on running in IJ 2019 JBR 11. Sometimes, my users accidentally start it under IJ 2019 JBR 8. When they do, one of two things happen, depending on which operating system they are running:
1. On Windows, IntelliJ appears to exit silently if it detects a problem with Java 11 executables in a jbr8 environment. Users wait for a long time, and try several times, and then report a "bug" that the IDE does not start up.
2. On Mac OS, IntelliJ pops up a modal window titled "JDK Required" that says "JDK classes seem to be not on IDEA classpath. Please ensure you run the IDE on JDK rather than JRE." The only response is "OK", which causes the code to exit the JVM. It is not clear that "OK" means "EXIT", and the root cause has nothing to do with the message displayed: they installed the wrong version of Idea.
Neither of these helps the user figure out the root cause. I put in code in my plugin startup to display a more meaningful message but IJ exits before my plugin starts up. I would suggest that on all operating systems, you pop up a modal window that tells the user he/she needs to run a different version of IJ. Then offer the response "EXIT" instead of "OK", so the user understands what is happening.