Should have the option for cancelling an install, as long as you are in the queue showing you what's currently updating. Send a pic of what you see when you see uninstall
I had the same issue when I tried installing rainbow its just a bug it will take you 1 to 2 days to install the update sadly just keep pausing and starting the update or leave it over night that's what I did it would get to about 60 and would say error update stopped went and looked and it was back to 40