Reported by desktop-file-validate:
error: value "True" for boolean key "NoDisplay" in group "Desktop
Entry" contains invalid characters, boolean values must be "false" or
"true"
While the new per-desktop overrides in GIO are easier to use for
both developers and users, it is still inconvenient for everyone
who changed the defaults using the old overrides hack to lose
their settings. Address this by running a small script on startup
that migrates existing settings.
https://bugzilla.gnome.org/show_bug.cgi?id=786496