Version 14 cannot connect to computers

My computer and all computers that I can control were on TeamViewer 13 with unattended access set up.   All are Windows 7 or 10 computers.  A new computer installed TeamViewer 14, and I had to convert my computer to TeamViewer 14 in order to access the new computer.  I converted to version 14 and was able to control the new computer that has version 14.  When I added this new computer to my list of computers & contacts, my list of other computers disappeared.  Now when I try to connect to any other computer (I put the ID in the box in the upper right corner and click the "connect" button), I get an "Unable to connect" message that says "TeamViewer not running on partner computer."  Help!  How do I access computers running version 13, and how do I get my list of computers & contacts back?