When upgrading Confluence, after backing up the data, it deletes the Confluence app directory and the installer fails.
I end up with a error.log file containing:
In action "Update JVM Options when upgrading JDK 8 to JDK 11 [Run script]" (screen "Upgrade Actions [Form]"), property "Script":
java.lang.NullPointerException
.....
 Using the openjdk version "11.0.8" 2020-07-14