Unable to agree

After successfully agreeing/commenting to various posts, I got the “Something has gone badly wrong” message at this post: https://www.ispotnature.org/communities/uk-and-ireland/view/observation/805586/ladybird,
I cleared the cache, and re-started Firefox. Now I see this message:

I can, however, add a comment to the post.

Updated: however, on this one,https://www.ispotnature.org/communities/uk-and-ireland/view/observation/805576/yellow-and-black-caterpillar
I can agree, but not add a comment:

I had a few problems this morning - plant carousel hung serveral times, main carousel once without thumbnails, error 500 on your iSpot, and empty profile.

These are very suggestive being Logged out. I notice for example that we can a have the site open in one Tab and if you close the Forum in another, then you will be logged out of the whole site, unknowing, until you wish to add something.
Actually logging out of the forum seems to log out of every occurrence of open iSpots - I found it useful! recently when I had loads of Tabs open

That’s possible: I had visited the forum before the “Something badly wrong” error, but had close Firefox and cleared the cache before re-entering the fray. Didn’t re-boot, however: perhaps I should have done.

All of the authentication is done through the website, not the forum.
Re-booting shouldn’t affect authentication but clearing your cache, if you also include the cookies, will certainly log you out.
Site “hangs”, which can result in the “500” error - are almost always due to the database being too slow to return data. We’re doubling the memory of all three of the database servers shortly so we hope this will improve matters.

Maybe but if I have the Site open in another Tab and I log OUT of the Forum, I also get logged out of the whole site. So, if I return to the open tab and offer an agreement, it fails in the way described above.
I have just tested it with FIVE open Tabs each at different Obs - they were ALL logged out when I logged out of the Forum.
(WIN10 and Chrome that is)
We are all holding our breath for tomorrow’s upgrade!

That makes sense because the cookie applies to the entire ispotnature.org domain (forum is merely a subdomain).
Upgrade: me too! The next major upgrade is storage space for images. We’re not on the verge of running out but as folks’ cameras get to be higher and higher resolution, the rate of space usage increases year by year.

MIGHT it not be wise to restrict the size of Upload photos? Cameras are producing larger files, upload speeds are increasing, we are (I am) getting more enthusiastic about number of Pix per Ob.

It might come to that, yes. An alternative is to post-process the very biggest files simply to reduce their storage requirements. But the post-processing is carried out by the webservers, and the more work they’re given to do, the slower they’ll get.