macOS editions released with fixed update checkers
Today updates to all extant macOS editions of Mountain Utilities applications were released:
All these updates can be downloaded from their respective download pages.
These updates should make the update checkers of these application work correctly again, at least on OS X 10.9 (Mavericks) and later.
See comment #8 in https://mountainutilities.eu/forums/i-get-error-opening-fcb1010-manager for full discussion.