A severe issue with the Basic and Master Palettes occurs every time I open Musescore Version: 126.96.36.19992, Revision: 57d770e.
Today, I installed the latest update. However, when I open Musescore, both Palettes were "blank, empty."
Step 1: Restarted the computer after the latest update installed.
Step 2: Opened Musescore 188.8.131.5292.
Step 3: Opened both Palettes. Basic is consistently "blank" and the Master Palette comes-and-goes.
Step 4: Repeated the process and got the same result.
Opened Musescore 10 times and still had NO information or functionality of the Palettes.
NOTE: The workaround was to Create a Custom Palette from the choices given.
Maybe, I should reinstall the update.