Dirlist example throws exceptions during execution

When running the Dirlist example and executing

`./bin/runex dirlist.Viewer....`

exceptions are thrown in the terminal window. The Viewer GUI appears to work properly but the exceptions should be examined more closely and resolved if possible.

Start by running `./bin/runex dirlist.Viewer....` and capture the terminal exceptions while confirming that the Dirlist Viewer GUI still works. Trace the reported failures from the `dirlist.Viewer` entry point; done means the exceptions are resolved or explained without breaking the GUI.

Written by the indexing model from the issue text.