>>567898
As a temporary workaround, you can install 4chan X and turn off "Show Upload Progress".

>>567904
test

>>567904
>>568118
Okay, I dunno what magic is it, but it works. Does it bypass CORS by using greasemonkey api?

>>568122
No, it's just a normal AJAX request. The issue is that in order to monitor the upload progress, since at that point it hasn't received headers giving it permission to read the request, it has to do an OPTIONS request to ask permission first, then make the POST request where it uploads the form contents. Something is going wrong with the OPTIONS request, I don't know what since I'm not in the affected area (Russia, it's been happening since the temporary ban after a DDoS). All I know is that it's the biggest difference between the way the form at the top of the page operates and how the quick reply operates. Maybe you could figure it out from your end.

>>568134
So you're saying the fault is with Russian ISPs?

>>568134
All I know is firefox and chromium claim that cross-origin requests are forbidden, while thread update works just fine. My mobile browser seems to don't care, though.

>>568149
Given it started after Russia was temporarily blocked on 4chan's end, it's more likely a configuration issue on 4chan's end.

>>568157
In the network part of the console, are the OPTIONS requests getting responses? If so, what headers is 4chan sending back?

File: Capture.png (10 KB, 422x198) Image search: [Google]

10 KB, 422x198

OPTIONS to sys.4chan.org/qa/post gets HTTP/1.1 403 Forbidden
Picrelated.