XF 1.5 Adding javascript to page_container_js_head, get "Security error occurred. Please press back[...]" no matter what I do.

[elsparkodiablo]

I'm switching ad providers and need to update the js in the header to call the correct banners. No matter what I do, I continually get captchas, then the above error (in plain text, not even HTML formatted) when I save the template. The template does not change, either.

Troubleshooting steps thus far:

• Ensured it's not cloudflare
• upgraded to latest XF1.5.24
• attempted in Chrome, captcha is simple 'check box to show you are human' - get error
• attempted in Chrome incognite, captcha does picture matching, same result
• attempted in Microsoft Edge, same captcha & error

 

[Russ]

When I've seen that in the past, it usually comes down to some sort of server-side firewall.

 

[m1ne]

Only CloudFlare would show captcha in this situation.

 

[elsparkodiablo]

Turns out that CloudFlare was blocking my IPv6 but not my IPv4