I chatted with darkweasel on irc. The summary version of it:

It appears that the files were successfully uploaded to Special:UploadStash. Presumably with ChunkedUpload since > 10 mb. However it appears that UploadWizard was never notified of the success. Either the PublishStashedFile job wasn't inserted/run/etc, or it didn't properly update the session thingy that includes the success status. We've received similar reports previous like this (previous reports were usually more for very large files though)

Given that bug 47312 seems to maybe suggest that sometimes inserted jobs just don't run, maybe there's a problem with job queue accidentally not running a job intermitently.

User also reported getting some "Internal error: Could not determine if the copy succeeded." but error went away on retry and was at beginning so not as big a deal.

[18:22] <bawolff> darkweasel: Would you mind going to https://commons.wikimedia.org/wiki/Special:UploadStash and seeing if any of your uploads that didn't work made it to that page (It might be helpful in debugging your issue, or it might not, but can't hurt)
[18:24] <darkweasel> bawolff, there are 15 files in that list
[18:24] <darkweasel> but if i click the first one it says it can't serve a file larger than some number of bytes
[18:24] <darkweasel> same for the second one and probably the rest, as they're all quite big
[18:24] <bawolff> yeah, the limit is insanely low (I think its 1mb), so that's ok
[18:24] <darkweasel> Internal Server Error
[18:24] <darkweasel>
[18:24] <darkweasel> Cannot serve a file larger than 1048576 bytes.
[18:26] <pleclown> Perhelion: 🐒
[18:26] <bawolff> darkweasel: On the side there is a "community tool" link thingy, if you click on it it should list a bunch of other data including file size (and sha1). You can use the file size aspect to see if the full file got uploaded
[18:26] <darkweasel> if i click that i even see plausible thumbnails
[18:27] <darkweasel> and the filesizes also appear plausible (10-15 mb)
[18:28] <darkweasel> i don't see an sha1 hash though, unless that's the filename?
[18:28] <bawolff> Umm, I don't think so, maybe its the other tool that gave sha1 hashes
[18:29] <darkweasel> 12bcw36ejkh8.o97nx9.512699.jpg
[18:29] <darkweasel> filenames look like this
[18:29] <bawolff> The 512699 is your user id
[18:30] <bawolff> No, the rest is random (its microtime() with a base change followed by mt_rand() with a base change)
[18:32] <darkweasel> ok - if it helps other developers (and even if not), you have permission to post (my parts of) this log into bugzilla or anywhere else btw
[18:32] <darkweasel> but do i see that right that i could continue the uploads from the uploadstash tool?
[18:33] <bawolff> yes. If you're feeling frustrated feel free to do that (Note that the description won't be copied over from upload wizard)
[18:33] <darkweasel> mhh no
[18:33] <darkweasel> apparently the arrow does something else
[18:33] <darkweasel> ah yeah
[18:33] <darkweasel> didn't see the publish link
[18:34] <bawolff> I have a really shitty tool that can get you the sha1 if you're really curious User:Bawolff/stash.js, but otherwise my tool sucks, especially compared to rillke's nice tool :)
[18:35] <darkweasel> yeah well if the thumbnail looks ok it should have been completely uploaded, so that's fine
[18:36] <bawolff> Special:UploadStash does also show partial uploads, but then the thumb wouldn't look right
[18:36] <darkweasel> yeah, bit hard to get a thumbnail from a partially uploaded file
[18:37] <bawolff> Actually it usually sort of works, the file looks half cut off
[18:37] <darkweasel> ah - well these don't :)
ah - well these don't :)
[18:39] <bawolff> darkweasel: So did all your files get to Special:UploadStash, or were there some that ended up just disapearing altogether
[18:39] <darkweasel> hmmm let me check
[18:42] <darkweasel> i think they're all either in there, or succeeded at my first try
[18:42] <darkweasel> some are in uploadstash more than once, because they failed more than once
[18:54] <darkweasel> yes
[18:54] <darkweasel> in the first step
[18:54] <darkweasel> when uploading
[18:55] <darkweasel> with just some files, not all - the rest worked fine, and when i then removed the ones where it didn't work and re-added them, it worked fine
[18:55] <darkweasel> so nothing really fatal there, just slightly annoying
[18:56] <bawolff> ok
[18:56] <darkweasel> ("it didn't work" means "i got that error" - sorry i'm losing my ability to word precisely at this time of day with too little sleep)

darkweasel.wikimedia.bugzilla wrote:

This does appear to be somewhat related to chunked uploads. I have now disabled them, and been trying to upload another set of files. The uploading did not work (at least not within reasonable time) when I selected them all at once, but did work when I selected them one-by-one.

Currently, three files are in the "submitting details and publishing" stage although a glance at my uploads shows that they (the ones starting with "Donau-Auen IMG" have in fact been successfully uploaded. It seems that the others will not be able to be successfully published in the same batch. :(

Obviously, Special:UploadStash does list these files.

darkweasel.wikimedia.bugzilla wrote:

Sorry, please ignore my previous comment for the most part. I had not precisely remembered the symptoms at the last time, and now that I'm rereading what I wrote, I'm noticing that they appear to still be the same, with or without chunked uploads.

This is almost certainly a duplicate of 71409, marking so.

• This bug has been marked as a duplicate of bug 71409 ***

Sorry, chaining of duplicates.

• This bug has been marked as a duplicate of bug 69374 ***