The thing is tabs uses cookie and cookie (now biscuit) file still uses the words cookie inside its code. I investigated the problem, others have had the same. It seems to be related to a false positive in mod_security2 with a copied and pasted set of rules. There is a bug in this specific one, I would suggest you remove this rule until we can get behind this if it causes allot of problems for you.
The thing is tabs uses cookie and cookie (now biscuit) file still uses the words cookie inside its code. I investigated the problem, others have had the same. It seems to be related to a false positive in mod_security2 with a copied and pasted set of rules. There is a bug in this specific one, I would suggest you remove this rule until we can get behind this if it causes allot of problems for you.