Source:
- https://youtrack.jetbrains.com/articles/SUPPORT-A-736/How-to-change-the-version-of-PlantUML-JAR-used-by-IntelliJ-IDEA
- https://youtrack.jetbrains.com/issue/IJPL-92405/PlantUML-theme-is-not-recognized-because-of-low-version-of-the-plugin#focus=Comments-27-5700177.0-0 for Mac specifics
TL;DR:
- The JAR is located in
~/Library/Caches/JetBrains/{Productname}/markdown/download/plantumllanguageextension/plantuml.jar
. - You can confirm the (old) version with
java -jar plantuml.jar --version
.