Not a valid enum value

[singularityhacker]

Two solid days of troubleshooting and I still can't get Meteor to upload some text files.
"The provided value 'undefined' is not a valid enum value of type XMLHttpRequestResponseType" error in cfs_upload-http.js. Judging from peoples comments online, this is just broken right now.

[ryanbuiltthat]

I'm getting the same error. It doesn't seem to affect whether an object is uploaded as far as I can see but it certainly isn't clear what's causing it.