MODX gives a 403 error when saving Templates

When I save a template I see a little 403 error notice appear in the modal, and, of course, my changes dont save.

This doesnt seem to happen with Resources or Chunks.

I tried clearing the cache, but the process hung so I cleared it manually and also cleared to browser cache to no affect.

Can anyone help me out here?

Does this happen when saving a minimal template (with nothing but simple HTML in it)? If not, it could be an issue with mod_security.

There's also the possibility that your date/timezone settings are not matching, though I'm not sure if that would give you a 403 error.

This was also happening to me recently.

I was getting the error when I created a new resource and then tried to change the template. The page would reload into a 403.

If I created the new resource and saved it (before trying to change the template) it would work. And after that I could change the template as normal and everything would work fine.

Not sure if related, but the installation where I am getting this problem is set up in the subfolder of a subdomain. ie: http://subdomain.yousite.com.au/subfolder/

I haven't found a fix yet :/