menulibre will add items but not delete them

Trying to delete items like menus and separators put me in an infinite confirm loop. Running menulibre from the command line instead of the settings menu, I found that the problem was that

~/.config/menus/applications-merged

and

~/.config/menus/applications-merged/xdg-desktop-menu-dummy.menu

were owned by root, with no g or o access. This was on Xubuntu 18.04.

ADDITIONAL PROBLEM:

Running menulibre from the command line, it first hung until I did

unsetenv LC_ALL

(was set to C). Last error message was "UnicodeDecodeError: 'locale' codec can't decode byte 0xe2 in position 13: Invalid or incomplete multibyte or wide character" before the hang.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: menulibre 2.2.0-1
ProcVersionSignature: Ubuntu 5.4.0-124.140~18.04.1-generic 5.4.195
Uname: Linux 5.4.0-124-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.28
Architecture: amd64
CurrentDesktop: XFCE
Date: Tue Aug 23 15:12:36 2022
InstallationDate: Installed on 2019-08-09 (1110 days ago)
InstallationMedia: Xubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
PackageArchitecture: all
SourcePackage: menulibre
UpgradeStatus: No upgrade log present (probably fresh install)