This is for mac users (like myself) especially.
I have noticed that when uploading an expansion file to the google developer console (from a mac computer), using safari or firefox tend to hang/crash these browsers. And i’m talking about trying +10 times to upload a big expansion file, wasting a good +30mins each time, only for the browser to pop up an error and abort the upload. Very frustrating indeed if you’re at 99%!
However, so far using google chrome browser to do expansion file uploads I have not had any such issues and they complete 100% without any browser error every time.
So not sure if it’s just the time of day, or pure luck, this might help anyone having problems trying to do their upload using safari or firefox.