Try the following:
1. Exit Visualize.
2. In Windows Explorer, type %localappdata%\SOLIDWORKS\SOLIDWORKS Visualize 2017 and hit enter.
This should resolve to a path like: C:\users\<your_username>\AppData\Local\SOLIDWORKS\SOLIDWORKS Visualize 2017
3. Delete all the .xml files in this location
4. Restart Visualize and try hide/show of palette again.
Whoops. Forgot the all important step of deleting the .xml files in that folder. This was likely obvious but I in fact did not actually indicate to o this. I have updated my steps in the above post, accordingly.
Dave - let us know if this works!
It worked-Thanks so much