After we pause when typing, a popup says we have a "runtime error." the pause may only be for a minute or so. Then, we cna't save what we've typed and it is lost. What is this about?

It sounds like this is a computer error, not necessarily related to word. You should probably run a virus scan just to rule any out. There are also different types of runtime error, it would be helpful if you took a screenshot of the error and posted it.