In case others hit this, I think I figured it out. I noticed my PATH was preferentially selecting the jre's java.exe. Even though I have JAVA_HOME set to the correct JDK directory, I'm hypothesizing that some script is trying to infer java_home based on the location of java.exe (some wrapper scripts do this). when i updated my PATH to preferentially use the JDK's java.exe, then tried to open this in intellij, things work properly.