XF 1.2 Attachments: "The file you have selected is too large"


A little while ago all our mobile Taptalk users reported that attachments stopped working. I cannot figure out why (this was unrelated to any changes to Tapatalk, in fact it was quite a few weeks before the latest Taptalk client update) as it seems to have happened entirely at random. The server error log reports nothing, either.

Testing out a 2mb image triggers this error even though the attachment size is set at 11mb in the ACP and phpinfo reports an uplolad_max_filesize of 256m. It either claims the file is too big or it just hangs.

We've added no other addons recently.