Created attachment 260262 [details] output from lldb bt all OS: FreeBSD 14.2 amd64 Hardware: a number Lenovo laptops Firefox-esr is installed in a vnet jail which is configured to use X-forwarding either through a socket (null-mounted), with xhost and DISPLAY set or through ssh -X. When firefox-esr is started it dies immediately with segmentation fault. Example: $ /usr/local/bin/firefox Crash Annotation GraphicsCriticalError: |[0][GFX1-]: Failed to initialize shared font list, falling back to in-process list. (t=0.742647) [GFX1-]: Failed to initialize shared font list, falling back to in-process list. Segmentation fault I get a core dump which shows pretty much nothing. I will attach the output from bt all. This problem seems to happen on firefox 136.x and newer, firefox-esr 128.x and librewolf 136.x and newer. I first experienced this with librewolf version 136.x and later with firefox 138.x. Yesterday I reinstalled my Lenovo T14 gen4 laptop with a fresh 14.2. It happens on 3 laptops I have tested this on (Lenovo T14 gen4, Lenovo Thinkpad Yoga 14 and a Lenovo x230). I have tested RAM on all three machines with memtest without issues. On the Yoga laptop I have a jail with firefox 135.x and firefox 136.x. Firefox 135.x does not die with segmentation fault 136.x does. On the same machine I built librewolf 138.x (from ports) with debugging enabled. This makes the problem go away. I don't know how to debug this any further. I am willing to test suggestions and provide feedback if the person asking for feedback is a bit patient (I can usually test and provide feedback in a week or two but sometimes life happens and it takes longer).