Try to enter about:config in the address bar and set security.enterprise_roots.enabled = true, then restart.

thanks for your replay I saw this option and it was the status TRUE. but still does not work for me. pls give me a roadmap for that. I do this: 1- I enabled the option "security.enterprise_roots.enabled" 2- I added our certificate to Windows certmng.exe 3- Restart Firefox 4- we searched a keyword and got an error "Error code: SEC_ERROR_BAD_SIGNATURE"

any help can be good

Hi

You should not need to alter about: config for this - you may wish to change that preference back.

Does this support article help?:

https://support.mozilla.org/en-US/kb/setting-certificate-authorities-firefox

Thanks for your replay Paul I did these steps and incredibly my certificate not showing and working. I read all the issues about this problem in WWW and tried to solve it with all solutions but it's not working for me. any hint can be happy to me I'm using Firefox 116 on Windows 10-x64 bit