XF 1.5 Recent problem

[ImDoc]

In the past few weeks at random times a user will create a thread that nobody can access. When trying to access it you get the error:

'You don't have permission to access /index.php on this server.'

There are no server errors listed and no matter what I try I can't access it to read or edit it. My only choice is to delete it. Has anyone experienced this and can shed some light on it?

 

[Mike]

What's the thread's URL?

This is very likely a false positive from mod_security. Your host should be able to identify the rule and disable it.