403 Forbidden

I just tried to change the settings on one of my blogs (reducing the number of days in which people can leave comments because I've been getting quite a lot of spam) and when I clicked on 'save settings' I got an error message. The page was completely blank apart from '403 Forbidden' at the top. I checked and the settings haven't been changed. Only just before that I had made the same change on another of my blogs which worked fine. The two blogs in question are:
https://toonsarahphotos.travellerspoint.com/ - changes saved successfully
https://toonsarahengland.travellerspoint.com/ - changes couldn't be saved

Any ideas why this is happening please?

I'm still having this problem - can anyone shed any light? It means I keep getting spam to moderate on that blog, which is a bit of a pain!

I tried today to change the setting to make it not possible for non members to comment, as an alternative to decreasing the time limit, but that didn't work either, I still got the error 403 message. I don't understand why that's happening just with this blog but not my others. The moderation of spam is becoming a daily chore so I really hope someone can help!

I'll send Peter an email.

Quoting Sander

I'll send Peter an email.

Thanks - I didn't like to bother him as I know he's been busy, but if it's not something others can advise on, that would be helpful

I've had a bit of a look into it but struggling to reproduce the problem. The error message indicates to me that it is actually at the firewall level where you are being blocked. Something about the request is clearly triggering the problem.

I've put in some extra logging to hopefully capture why it is triggering that. Can you try it again. Hopefully it throws the same error so I can see the issue.

Quoting Peter

I've had a bit of a look into it but struggling to reproduce the problem. The error message indicates to me that it is actually at the firewall level where you are being blocked. Something about the request is clearly triggering the problem.

I've put in some extra logging to hopefully capture why it is triggering that. Can you try it again. Hopefully it throws the same error so I can see the issue.

Thanks for trying. Surely if it were a firewall problem it would have happened when I changed the same setting on my other blogs?

Anyway, as requested I just tried again and got the same message. Does that help you to investigate further? Alternatively, is this a setting you can change from your end?

The firewall checks more than just the IP address you're coming from. It has a whole bunch of rules that are meant to detect malicious activity. But maybe there is something that triggered it for this one. I'll have a look at the logs to see if there is any explanation in there!

It quite possibly is a setting, but the trick here is working out which setting it is

Thanks Peter

Well I found it and as suspected it was blocked by the firewall. But it's totally unclear to me why. One possibility is that something in your cookies is causing it to be triggered. Could you perhaps try accessing the site from an incognito window (in Chrome it's File > New Incognito Window)? You will need to log in again. I'd be interested to know if the error still occurs. If it doesn't then it's almost guaranteed to be something to do with cookies.

I'll leave the firewall rule up until you've had a chance to check this. And in the meanwhile I'll get in touch with Amazon who manages this rule to see if they can give me any clues.