The exception illegal instruction
We have had FireFox as a published Citrix app for our users for years. As of Friday (10/13/17) users started getting an application error upon startup - The exception Illegal Instruction. FireFox is installed on two of our Citrix servers (2008 R2) and cannot run locally, as admin, in safe mode, and after refresh.
Currently running up to date version 56.0.1 (64bit). No updates or changes to the servers or Windows have occurred prior to FireFox error. I cannot find anyone else on the web having this issue either.
All Replies (3)
For some reason I couldn't upload the screenshot of the error the first time. Here it is:
I have the same issue with Firefox on Citrix, seems to have started with ver 56.0.1. Happens on all 6 Citrix servers in the farm. Can find nothing in Application or System logs. No crash reports either.
Citrix XenApp 6.0 running on Server 2008 R2 Standard. 64-bit Firefox, now on 56.0.2.
My organization prioritizes security so downgrading to an earlier version is not an option.
Modified by ecirs
Happy112 with the solution here:
https://support.mozilla.org/en-US/questions/1180385#answer-1021637
Follow that article to the linked Citrix article and disable XenApp API hooks for firefox.exe.