FIX Secure Connection Failed Firefox Error code SEC ERROR OCSP INVALID SIGNING CERT.
If Firefox can't access a secure site (one that starts with https) you will see an error page with the heading Secure Connection Failed and a message about the error.
An error occurred during a connection to microsoft.com. Invalid OCSP signing certificate in OCSP response. Error code: SEC_ERROR_OCSP_INVALID_SIGNING_CERT
This tutorial will apply for computers, laptops, desktops,and tablets running the Windows 10 operating system (Home, Professional, Enterprise, Education) from all supported hardware manufactures, like Dell, HP, Acer, Asus, Toshiba,Lenovo, and Samsung).