Hello, the plugin justified gallery is not correctly installed.
In different browsers says the same thing when you install the plugin “ERR_CONNECTION_RESET”
Using the standard settings panel of the plugin it is not installed at all “connection brosenne”
If you upload the plugin via FTP, it appears in plugins, and activated. but not correct when clicking on the link “settings” window appears “Sorry, you are not allowed to view this page” .
The wordpress version is 4.8.2