Namebench won't close - "main thread is not in loop"

[Jeb E.]

Namebench errors out when I try to close the program. See the output information listed below from my Terminal during the time I attempted to close the program:

"
> Checking nameserver availability (6 threads)... [582/4516]
Au revoir, mes amis!
Traceback (most recent call last):
  File "/usr/share/namebench/libnamebench/tk.py", line 118, in run
    self.PrepareNameServers()
  File "/usr/share/namebench/libnamebench/base_ui.py", line 111, in PrepareNameServers
    self.nameservers.CheckHealth(primary_checks, secondary_checks, censor_tests=censor_tests)
  File "/usr/share/namebench/libnamebench/nameserver_list.py", line 416, in CheckHealth
    self.PingNameServers()
  File "/usr/share/namebench/libnamebench/nameserver_list.py", line 645, in PingNameServers
    results = self._LaunchQueryThreads('ping', 'Checking nameserver availability', list(self))
  File "/usr/share/namebench/libnamebench/nameserver_list.py", line 612, in _LaunchQueryThreads
    self.msg(status_message, count=results_queue.qsize(), total=len(items))
  File "/usr/share/namebench/libnamebench/nameserver_list.py", line 239, in msg
    self.status_callback(msg, count=count, total=total, **kwargs)
  File "/usr/share/namebench/libnamebench/base_ui.py", line 56, in UpdateStatus
    self.status_callback(msg, **kwargs)
  File "/usr/share/namebench/libnamebench/tk.py", line 112, in msg
    return AddMsg(message, master=self.master, backup_notifier=self.backup_notifier, **kwargs)
  File "/usr/share/namebench/libnamebench/tk.py", line 60, in AddMsg
    master.event_generate('<<msg>>', when='tail')
  File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1512, in event_generate
    self.tk.call(args)
RuntimeError: main thread is not in main loop
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
    self.run()
  File "/usr/share/namebench/libnamebench/tk.py", line 134, in run
    self.msg(exception, error=error_msg)
  File "/usr/share/namebench/libnamebench/tk.py", line 112, in msg
    return AddMsg(message, master=self.master, backup_notifier=self.backup_notifier, **kwargs)
  File "/usr/share/namebench/libnamebench/tk.py", line 60, in AddMsg
    master.event_generate('<<msg>>', when='tail')
  File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1512, in event_generate
    self.tk.call(args)
RuntimeError: main thread is not in main loop
"

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: namebench 1.3.1+dfsg-2
ProcVersionSignature: Ubuntu 4.13.0-36.40-lowlatency 4.13.13
Uname: Linux 4.13.0-36-lowlatency x86_64
ApportVersion: 2.20.7-0ubuntu3.7
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Sat Mar 3 08:05:56 2018
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: namebench
UpgradeStatus: No upgrade log present (probably fresh install)