We have seen a couple of users with corrupt entries in their sharedconfig.vdf file causing this issue where the configuration screen loads indefinitely.

Please note: This process will delete all of your controller configs:

Find your sharedconfig.vdf here: (relevant hard drive)...Steam/userdata/[AccountID]/7/remote/sharedconfig.vdf

Open sharedconfig.vdf with a text editor (notepad should work). All of your Steam Controller configs should be stored here.
Search for the heading “controller_config”, then remove the blocks of text belonging to it (any text preceding the next heading), save and close the file, then restart Steam.

Just to be sure, you'll have to delete the entire block that reads something like this:

"406970"
{
"usetime" "1847.5078125"
"selected" "workshop://the uncertain gamepad_0.vdf"
"enablerumble" "0"
"rumbleintensity" "320"
}

In the case above, you'd make sure to remove the section: "workshop://the uncertain gamepad_0.vdf" along with the entirety of the block.