Good day. I hope I am in the right place. I am on Moodle 3.6 and tried to install the plugin “Custom certificate” which I did not succeed in. I then deleted the plugin (I think). I tried to do a new installation of the plugin but now I can't access my site administration. I constantly get the following message: core_plugin/err_unknown_plugin
I have no idea how to fix this.
Please help.
I suffered from this issue. I installed both of the certificate plugins and everything seemed to be working fine until a couple of days later - when I went to site admin, I got the core_plugin/err_unknown_plugin error screen - so I couldn't access any of the site admin, but the front page courses were still working. I looked into trying to uninstall the plugins via ftp / command line which all seemed too complicated and dangerous. I had recently upgraded Moodle and noticed there was a minor upgrade available so I let installatron upgrade (from 3.9 to 3.9.1). This seems to have fixed the issue. Hopefully now I'll be able to uninstall the certificate plugins that have caused the issue.
