This might be related to the Widevine CDM revocation on 1/20. I had this error consistently until I grabbed an updated CDM (4.10.2934.0) from a local Brave install and copied it to the StreamFab install. This can also be found in Chrome or Firefox. Check that your browser is updated first to make sure the latest CDM is installed.
Brave: %USERPROFILE%\AppData\Local\BraveSoftware\Brave-Browser\User Data\WidevineCdm
Chrome: %USERPROFILE%\AppData\Local\CEF\User Data\WidevineCdm
Destination: C:\Program Files\DVDFab\StreamFab\CEF\WidevineCdm