failed to publish
I dunno if you'll find this helpful, but in a map I'm working on, I had difficulties uploading it too. I found that when I removed a texture that was quite large (19mb) for a texture, the map was able to be published. Anyone having this issue may have the issue of the publisher timing out (I believe it has a timer, don't quote me on that).
Hope that helps!
GUYS! to me it worked out just now! Maybe it's fixed!
QUICKLY! PUBLISH!! RUN RUN RUN!! 
useful tools and stuff here on TWP 
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Ehhhh... I haven't been able to upload anything for a really long time, and still its not working. Is there anything you guys did to fix your publishers?
Aperture Science: We do our science asbestos we can!
Maybe you should check to update steam?
Bit of a late response on my part but what I ended up doing is weighing down my Enter key and walking away for a while
Just make sure holding down Enter does in fact advance through all the menus properly; if not you may need to set up a script to spam the Enter key.
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Maybe you should check to update steam?
Done that, I'm not sure what else to do, other than putting a rock on the enter key, which i don't really want to resort to.
Aperture Science: We do our science asbestos we can!