We use 'crash' for, on Window, a process stopping either with no explanation or a 'Your process has stopped box' from Windows.

In any case, PositionalList.py will not run without _DoublyLinkedBase.py, which you did not upload.

The traceback has
  File "...\Python\Python36\lib\bdb.py", line 48, in trace_dispatch
    return self.dispatch_line(frame)

Since sometime last summer, that code line is line 51, indicating that you are using an old release of 3.6, probably 3.6.2 or earlier.  The current bugfix release is 3.6.5.  If possible, upgrade to 3.6.5 and retest.

The traceback does not make much sense to me either.  Neither of the IDLE methods userline and interaction obviously access a .name attribute of anything.  The '_ModuleLock' object is created by importlib._bootstrap.  Searching all issues for '_ModuleLock' got 11 hits.  None are obviously about import and tracing.

To determine whether the problem has anything to do with IDLE, single-step debugging should be repeated with pdb, which is Python's text debugger, and also based on bdb.

Brett, can you tell anything from the multiple importlib._bootstrap lines in the traceback?