Relevant to Firefox running on Ubuntu 22.04 Linux and an x86_64 platform. Until roughly 2/2026, it was possible to load a security device by opening Settings, Privacy and Security, Security Devices, then browsing to a shared pkcs11 shared library, in my case /usr/lib/x86_64-linux-gnu/opensc-pkcs11.so, and clicking Load. The shared library would load and would be loaded subsequently whenever Firefox was started. For roughly the last two months, Firefox would pop up an error saying it was not possible to load the security device, but it would actually be loaded and it;s functionality would be available for the current session. For the last two weeks, the library would load without error, but only for the current session. Starting on 4/13/2026, some functions in opensc-pkcs11.so work, but not others. For example, it is no longer possible to connect to MS Teams web interface.