Do you have cloudflare? They were having problems yesterday- unsure if they were solved- I'm guessing they were at some point.

I don't have cloudflare.

It is wrong to blame this mod for this error as I am not entirely sure what the problem is yet.

not working for me , or I don't understand well
testing thread that is hidden from guest or it has been deleted
like this
http://www.gem-flash.com/vb/showthread.php?t=1
http://httpstatus.io/ said 404
also google webmaster said not found

I have DBoptimize, DBSEO, XCache all enabled

404 means it is working, at leas partially. If it wasn't working it would show 200.

The exact code it should show in this case is configurable in settings.

so to be useful from the mod
change all status to 200 ?

its realy working when change Generic Error HTTP Code to 200 , its wokring and send 200 status
what should I do then , change all to 200 ?
your site is sending 404 in your wrong thread

If you disable the mod Google will get 200.

The purpose of this mod is to change 200 to 404 (or some other number.)

When google gets 200 but can'tr read the thread it's considered a "soft 404" error which is bad for SEO.

When google gets a 404 it knows it is a bad page and stops looking for it- it is less bad for SEO.

thanks for your reply
I want to know something about another error
vb/showthread.php?t=222053
this thread is hidden from guest
and from HTTP status got error 403

is that normal ? and good for seo ?

403 is again from this mod and yes it is better Google sees a 403 than a 200 on a page they cannot read the real content of.

Could you add a rewrite rule to your .htaccess file that directs all 200 pages to 403 pages instead of insalling this mod? Was curious about what difference it would make.

All "200" pages would mean every page on your site- that would be worse than not doing anything at all.