Comment to Using tags in html and raw blocks
Could you please try to insert this code into .htaccess in root folder of your domain:
<IfModule mod_security.c>
SecFilterEngine Off
SecFilterScanPOST Off
</IfModule>
Thanks for your help, but that still didn't fix it :(
Do I need to download the mod_security.c file and put it somewhere? I don't see it in the UNA installation anywhere, but I don't see a security module in the Apps Market either...