We can provide two alternative solutions for certificate errors:
1. Go to Tools - Options - Privacy Content tab, open Certificates, select the certificate there and select the Remove option. Enter the website where you received the error and accept it permanently when you want to sign the certificate.
2. Control date and hour settings of your computer, correct if wrong.
If your problem is not resolved, we recommend that you remove Zula from the computer by manually deleting the IDCGames folder in the C: directory and download it with the installation manager and install a clean installation.