Your copy of TeamViewer is not compatible with the custom version we use at Birder's Diary.
So, if you have TeamViewer installed on your computer, you will need to simply Exit the running program. No need to uninstall it.
Do this by locating the TeamViewer icon in the lower right portion of your screen where the date/time are displayed.
Now right-click on the TeamViewer icon and choose Exit from the popup menu.
Now you can connect to Birder's Diary support via the instructions above.