There are two main reasons that can cause you to lose access to the GUI.
1.- When the server runs out of space on the hard disk, this causes mariadb to stop, therefore we will not be able to access the web interface.
Enter by SHH and verify if this is the Issue by executing the following command:
If we see that there is no space available on our hard drive, we can delete some not important files such as the logs found in the following path:
On many occasions it is necessary to delete old recordings found in the following route
After freeing up some space we can restart mariadb
systemctl restart mariadb
2.- It was not possible to renew the Lets Encrypt certificate.
If you have installed the GeoFirewall module, do not block the USA, since the let’s Encrypt server needs access to create or renew the certificate and these servers are generally in the USA.
If you cannot enter the interface because the certificate expired and it cannot be renewed, we recommend doing a configuration reset and re-creating the certificate from the interface. For this we use the following command from the console: