File uploads on issue queue

Today I'm getting errors repeatedly, while uploading patches (attachments) to the issue queue:

The selected file /tmp/tmp_XUZs1C could not be uploaded, because the destination files/issues/js-css-reloads.patch is not properly configured.

File attachments are disabled. The issue directory has not been properly configured. Please contact the site administrator.

The second one most frequently. But still, I was able to attach the file later, through editing my previous comment.

Also I experienced a few times before, that I uploaded a file, it was there on previews, but gone after the post was submitted. I'm not the only one, I saw also others complaining on the issues. I suspect, that we actually got the error in these cases too, but didn't notice the message, being instantly sent down to the just-posted new comment at the end of long thread.