A minor bug I happened to encounter while uploading a creation to MTS a couple of days ago.
If the first files to be attached to the thread are *.zip/*.rar/*.7z archives, they do not show up in the "Attached files" area until the first image is uploaded. If the images go first, than the archives show up fine.
If it helps somehow, I'm using Google Chrome 56.0.2924.87 and running under Win 8.1.
Please, have a look at it.
Thanks for the report - that is a bit odd. I'd imagine it might have to do with caching. I'm going to be switching out the uploader completely for a different one real soon now (tm) so this will be fixed in the future.