A HTTPS server I'm browsing uses an invalid certificate. I want my machine to ignore this error and think that the certificate is valid. How to do that?
It will depend on each browser. Your server has a certificate, but each browser will display that this certificate was generated by an unknown authority.
Personally, I run a private cloud which is accessible only within my network. I know that it communicates with a secure connection and that the certificate was self generated by the server. Knowing this, I know that my connection is still encrypted but is not authorized/verified with a known agent. I will always get these errors.
However, it is not a good idea to disable the error/warning as that is no different than removing your Check Engine light bulb. Hides the problem but does not solve your root issue.
This part will allow you to add the exception for the certificate and not display this information again while keeping the connection secured.