Quick update. It’s not copy and pasting text that causes the issue. It’s copy and pasting URL’s that will cause that issue for creating a post. If I try to Edit a post, the post will simply refuse to edit.

Well that’s a new one on me!
Will probably need to take this one step at a time.
Is this true of ANY content you try and paste in or has this only happened with the same content?

Yes, I am duplicating this problem creating a post with ANY link from any site, with http:// inserted. I am also currently using Plain Text as default (current) editor. 

Wonder if this has anything to do with? 

No that wont be an issue.
Could we have a link to your forum page. Might be able to spot something – you never know.

Sure! Here you go

http://tarciryanknights.com/forums

well there are some script issues with your site which may be a factor. I kind of doubt it to be honest but these can get in the way of all sorts of operations.

Yoir site – theme or another plugin? is loading an incorrect version of the jQuery UI core library (calling it ‘personalised’ whatever that means or contains?) The problem is explianed here: http://codex.simple-press.com/codex/faq/troubleshooting/what-is-this-jquery-conflict/

I would also suggest you turn off the ‘minify’ tool. The vast majoroty of the scripts you are loading are compressed anyway so it is unnecessary and meaningless.

I removed the .js and line of php code requiring the personalized script you mentioned. I also removed Minify, but alas no changes.

I also tried turning off the theme and switching to others, I still get the same blank page with error message. Doesn’t seem to be theme related. 

errors look cleared up… but we cannot test since guests cannot post…

is your server by any chance running mod_security or other module that might be limiting the passing of POST data?

Yes the host is using mod_security. Is there any alternatives to disabling mod security?

Hey guys,

I had my provide disable mod_security. It seems that the problem is fixed and the POST variables were indeed being blocked by modsecurity. I hope there is an alternate solution so I can re-enable it again some time.

That rather depends on your host. In my limited experience most hosts are aware that mod_security is the bane of every developers life and – at the end of the day – a right pain in the backside for most people. And they are usually willing to whitelist out the rules they have imposed that breaks a users website. So if they are prepared to do that then you have the best of both worlds.

Yellow Swordfish said 

That rather depends on your host. In my limited experience most hosts are aware that mod_security is the bane of every developers life and – at the end of the day – a right pain in the backside for most people. And they are usually willing to whitelist out the rules they have imposed that breaks a users website. So if they are prepared to do that then you have the best of both worlds.

Makes sense. Thanks for your help guys! Cheers 🙂

You’re welcome. Glad we resolved it in the end.