Since v20.10, every new cloud instance with the Advanced Configuration Editor installed throws the NullReferenceException ("Object reference not set to an instance of an object") whenever any of the menus under the "Application Configuration" or "Disable Host Client Menu Items" headings are clicked on.
Previously, I had reported the same error with regard to trial instances, but since then I've determined that this bug actually affects all new cloud instances on v20.10 or over.
Existing instances which were initially created on versions before v20.10 and had Advanced Configuration Editor installed aren't affected by this bug, even when they've been updated to v20.10 and over.
I believe this bug is due to missing values in the app.config file. I say this because the "Web Configuration" menus used to be the ones that threw this NullReferenceException until that bug was fixed a couple of months ago and I remember the cause of that bug being missing values in the web.config file.
Customer support service by UserEcho