We just pushed a new release to the site. It appears to take care of the reports of not being able to open a new route after it has been saved. Thanks to the two folks who PM'd me with details.
We still recommend that you save frequently. There may still be a gremlin floating around where saving may fail. You don't want to be caught out with hours of unsaved work. "Save early, save often" as they used to say.
We plan on implementing an auto-save function as well.