Unable to connect: network address problem?

Hi there,

I work remotely as communications director for a family of veterinary hospitals. When we set this position up a year and a half ago, our "IT guy" set up TeamViewer so that I could remote in. Just this week, I started getting the Unable to Connect message: "Partner could not be contacted at the given network address"

The guy who set this up is no longer with the hospital, so I'm hoping to find suggestions here that I can use to work with the staff on-site to regain the connection. I'd really like to avoid having to drive 60 miles to fix it in person.

Thank you!