I would focus on the crashing first and see if fixing that fixes the other problem.
Is there something you know of that forces a crash?
Do you only work on one project? If more than one, does it occur with any project or any project. If only one, try working on one of the sample projects for a while. Click Open on the RoboHelp Starter page and then click Samples in the ribbon on the left.
What operating system are you using?
Where is your project located?
See www.grainge.org for RoboHelp and Authoring tips