Server freezes when ever I try to create new files or folders using admin plugin

I have not tried it using other methods. But this is annoying. Server freezes up and then takes 2-3 hrs to get back to usable condition again.
Side note. After login in. Admin panel shows error "403". Can provide additional details when server is up again.

Just found out that it only freezes from my IP. Site is still accessible from other IPs. Therefore I am thinking that the server is not freezing. Any ideas as to what might be causing this? Ping timed out from my IP.

This is the error that shows up when I login
http://imgur.com/a/HAVwb
Can anyone help me diagnose this problem?
My best guess is there is a read-only access problem somewhere. This is why whenever I try to create new posts the server hangs.

Found my problem
https://learn.getgrav.org/troubleshooting/common-problems#fetch-failed
Don't know how to fix this
https://github.com/getgrav/grav-plugin-admin/issues/951

This is the first time I hear about this problem. Is mod_security installed on your server, so maybe the server blocks you from contacting it again?