[Nathan2006]

Originally Posted by Marco van Herwaarden

Then it is very likely that it is a server issue.

Please try first by turning off GZip compression in your vBulletin Options.

Other things that might cause something like this:
- A .htaccess rewrite rule playing games
- mod_security settings if this is installed
- memory settings (doubt it in this case)

I very much doubt that this got anything to do with this modification. Can you (fake) edit other products? Are you having more problems with sometimes getting this kind of errors.

I got it sorted

Its was something to do with the mod_security setup on the server
and they have sorted it all and everything is good

Thanks