Install Extension - 403 Access Denied error

[Chuck4772]

I think EspoCRM is an excellent CRM to be the cornerstone of any business that has customers. For that reason, we are going to invest energy to make it work for our brokerage business. We want to use the Real Estate extension, but when uploading the zip file, we run across the Access Denied error.
My EspoCRM user had admin rights, and the Linux permissions for app modules are 775.
I have already disabled Modsecurity for my domain and enabled database logging. However this is still not working.

Has anyone experienced this or how should I try to get this extension installed?

[shalmaxb]

Look into the log file (data -> logs -> most recent file
If you don`t understand, what the log file says, post it here