Thunar 1.8.3 (in current) gives this error if using Cinnamon 4.0.9:
Code:
(thunar:28164): thunar-CRITICAL **: 12:08:49.580: Name 'org.freedesktop.FileManager1' lost on the message dbus, exiting.
Thunar cannot be launched anymore because thunar and nemo is fighting about who gets to be org.freedesktop.FileManager1.
It seems to be a Thunar-specific bug. It should be fixed if using Thunar 1.8.4.