Yina, are you experiencing this issue when uploading files from a laptop / desktop device, or primarily from Mobile devices (which likely have a slower internet connection)? How long (on average) is it taking to get to 80/90% done with the upload before it “stops”?

Hey Zach, I’m doing this from a desktop, it stays at 80-90% completion rate and it doesn’t move at all and when I log out and log back in to the account, the file is not attached. 

Hi Yina, my question is, how much time (e.g. 1 second, 15 seconds) is it taking to get to 80-90% completion? 

When this happens, can you open the JavaScript Console (Cmd+Shift+J on Chrome on a Mac) in your browser and see if there are any red error messages? If so can you post them here? Thanks.

Hey Zach, here is the error -

POST https://scafull-thesca.cs15.force.com/services/data/v33.0/sobjects/Attachment 503 (Service Unavailable)uploadBlob @ skuid__SkuidMobileJS:46FileUploader.restUpload @ skuid__SkuidMobileJS:46e @ skuid__SkuidMobileJS:46o.event.dispatch @ skuid__JQuery:3r.handle @ skuid__JQuery:3UpdateApplication:2 Uncaught SyntaxError: Unexpected token <(anonymous function) @ skuid__SkuidMobileJS:46(anonymous function) @ skuid__JQuery:3j @ skuid__JQuery:3k.fireWith @ skuid__JQuery:3e.(anonymous function) @ skuid__JQuery:3g.onreadystatechange @ skuid__SkuidMobileJS:46

Here’s a screenshot -

Thanks Yina this is very helpful! Can you check to see if the Profile(s) of your Community Users has the “API Enabled” Profile permission? If not this may be the problem right now. You could add this Permission to the Profile to fix the issue.

We’ll be making a fix in Banzai Update 2 that should address this issue without the need to add the API Enabled permission to your users’ profiles.

API is enabled for the running user

Yina, which version of Skuid are you running? 
Can you Grant Login Access to Skuid Support so we can take a look at this?

7.12 is installed, login access granted for 3 days, org ID - 00De0000005Vw7i

Behavior is still the same

This has been resolved in Banzai Update 3, which will be available from the Skuid Releases page by close of business today, October 2, 2015.