After I updated the firmware on My Cloud device it skips past the the sign in screen to a blank web page.
Welcome to the WD Community.
After the firmware update, have you tried resetting the unit? This will help the unit to clear any previews firmware information.
Did not work
Are you able to test that with multiple browsers?
I had the same problem when i did a firmware downgrade. I was only able to fix it by doing a power on factory restore (which means holding the reset while plugging in power cable and continue holding for 40 seconds). I didn’t lose any data in the process (but you may lose your configuration).
After that you can reinstall latest firmware again.
All of a sudden it start working.
However now my user id’s get all mixed up.
I deleted them and started over but it came back very flakey firmware