[Paul Stenning]

The server uses a system called ModSecurity which attempts to block malicious commands in website posts and URLs etc that could do harm if the website wasn’t well coded.

Issues we have had previously have been text that appears to be like email headers, SQL queries and Linux shell commands etc.

It doesn’t know whether the text could cause harm, it just blocks regardless before it even gets to the website code, hence the 403 server errors. It’s rule based and the usual fix is to have the offending rule that’s giving a false positive disabled for this website only. Before that can be done I need to narrow it down to a short piece of text that causes the problem consistently that I can send to the hosting company so they can reproduce the error.

Some of the text that is in your examples does look like the sort of thing that could potentially hit one of the ModSecurity rules. Because it is quite obscure and not typical text that would be posted, it may not be possible or sensible to have the relevant rules disabled (the hosting company have the final say).

My suggestion is to try again, perhaps writing it in a word processor first and just copying and pasting. Use the preview facility and if you hit the error then remove one paragraph or sentence at a time to narrow it down, and see if you can change the offending part. Alternatively put the offending part or the whole thing in an attachment such as a PDF.

If you do find the specific culprit please let me know, you can PM me for my email address (as you won’t be able to send it by PM either).