XF 1.5 forum returning 403 error all of a sudden?

[gtrgriff3]

One of my forums that has been working fine until a couple of days ago is all of a sudden giving a 403 error.

All other forums work, nothing has changed on the server side, and this forum has worked without a hitch for months so I don't know what changed. Any suggestions?

 

[gtrgriff3]

Sorry, maybe it's not a 403, I get the error:

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

And, like I said, there are 20+ other forums that work fine so it seems odd.

 

[gtrgriff3]

More info in case it helps:

The forum is at http://bluesguitarunleashed.com/forum

A working URL - http://bluesguitarunleashed.com/for...atonic-scales-technique-mastery-questions.46/
The broken URL - http://bluesguitarunleashed.com/forum/index.php?forums/everything-else.68/

I can't figure it out at all, this is way over my head.

Thanks for your help.

 

[Paul B]

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

That is a server issue typically due to something like mod security.

Contact your host and they will be able to resolve it for you.

 

[gtrgriff3]

Yes, I've seen that reply on other similar posts... but if nothing has changed how would it all of a sudden stop working?

I'm on a dedicated machine and the index.php url never changes, only the argument changes so I don't understand how mod_security would affect it, and more importantly why it would not affect it for months and then all of a sudden be an issue. Can you elaborate so I can do a better job of approaching the right person about this?

 

[Paul B]

but if nothing has changed how would it all of a sudden stop working?

It's a server level issue, nothing to do with XF, so whatever has caused it is something on the server.