The suggested steps did not work, so I blitzed my old install and did a fresh new install. It installed 11.05, then immediately ran the update for 11.20.
The Weather Customize button still does nothing. The Date and Time button in the adjacent window turns a lighter gray when the mouse enters it and it turns to a pointing finger. That doesn't happen on the customize button for weather. The mouse pointer does not change, the shading on the button does not change. It acts as though there is no button there.
I've customized the weather in the previous version without an issue.
Any ideas what I can try?