As of 26 September 2020 the webpage with version information for the java package consists almost entirely out of javascript. This results in unuseable scan values. A solution is being developed.
Should be fixed in version 2.1.0.
If you use the -7 switch to force the installation of Java 7 instead of Java 8, the temporary directory isn't cleared, which can lead to install problems.
Quick fix: always use -cr7 instead of -7 (and -cr if you want to switch back to Java 8 after having installed Java 7).
In version 1.3.1 this has been fixed to the extent that the -7 switch now includes both -c and -r. Switching back to Java 8, you still have to specify these options manually.