Recently a client was attempting to create a post from within admin and was given this error message Your IP address has been banned from this site or you are not allowed to access this page, yet he was the owner of the site.
I sent the client through some debug routines that were unsuccessful, checking for plugin conflicts, thinking it might be related to WordFence.
Turns out the client was able to solve this by contacting their hosting provider and discovered that this issue was related to “Login Protector”, a HostMonster specific tool.
I’m recording this for record seeing as Google did not have any accurate leads for me at the time.