I ran into a bit of difficulty trying to get CLIJ2 up and running. I eventually got it up and running, maybe this is usefull for someone else running into a similar problem.
Each time I ran
run("CLIJ2 Macro Extensions", "cl_device=");
Fiji crashed immediately (closed without notice).
The error log (hs_err_pidxxx.log in Fiji.app folder) pointed to:
# Java VM: Java HotSpot(TM) 64-Bit Server VM (25.172-b11 mixed mode windows-amd64 ) # Problematic frame: # C [igdrclneo64.dll+0x30819]
Which turned out to be a problem with an unused Intel display driver:
After running the display-driver-uninstaller and removing the Intel driver everything worked like a charm.