After adding the Java 8 update site I ended up with a non-working Fiji.
Trying to look for a solution I landed on this page
Unfortunately it does not provide the latest Fiji download (at least for linux 64) and causes the same non-working install (due to the lack of Java 8).
Perhaps it need updating or linking to the right downloads by somebody who is sure what the “always up to date” links should be (I am not, sorry!).