Distribution:  Xubuntu 18.10
xfce4-taskmanager Version:  1.2.1-1

I repeatedly crashed xfce4-taskmanager by starting the XFCE Task Manager, starting the Steam client, and closing the Steam client windows. It does not matter what Steam client window is closed whether it be the "Create/Login existing", "Login credentials", or main main Steam client window. dmesg logs always showed the following when the task manager crashed. Repeated crashes did not change the code produced:

[ 538.849213] xfce4-taskmanag[14268]: segfault at 0 ip 0000558eda955a23 sp 00007ffd6c79c000 error 4 in xfce4-taskmanager[558eda948000+f000]
[ 538.849216] Code: fb 48 83 ec 08 e8 ed 2e ff ff 85 c0 74 09 48 83 c4 08 5b 5d c3 66 90 e8 db 32 ff ff 48 89 df 48 89 c5 e8 b0 36 ff ff 48 89 ee <48> 8b 38 e8 85 29 ff ff 48 83 c4 08 5b 48 89 c7 5d e9 97 3c ff ff

#### Steps for reproducing this issue:
1. Open XFCE Task Manager (xfce4-taskmanager).
2. Start the Steam client.
3. Close the Steam client by using the top right corner X on any of the windows.
4. Crash Task Manager.
5. Repeat.

Also reported here:  https://github.com/ValveSoftware/steam-for-linux/issues/6083