403 error if plugin is disabled or removed

Hi,

I have used this plugin for many months now, and after my site turned to https I have had some problems.

The SSL-certificate installation was performed by my host to all its customers, and I have no reason to believe that there were any errors in the process. All the rest of the loose ends were fixed by me.

The thing is, if I need to disable this plugin, or to remove it completely for some reason, I get 403 forbidden error. Re-installing the plugin doesn’t fix the issue. Only way to recover is from backup.

I’m quite puzzled what might be the core reason of the problem, but it clearly started after implementing the https.

What could be causing this?