I tried to upload 16MB file to Wikimedia Commons which queued a long time and then failed with "Unknown error $1". (error view as a screenshot F29604690) I tried to upload it to beta commons too and it failed in there too. Smaller file worked ok.
Upload time with commons.wikimedia.org : 2019-06-19 09.29 UTC
Upload user name: Zache
File name: DSC5159.jpg
Browser: Chrome 74.0.3729.169 (64 Bit)
OS: Windows 7
Btw. I tried to upload file to this phabricator ticked and it failed too. (see a F29604707 screenshot for an error message)