Google quite often increases the otho-imagery version number in the URL. You can fix this yourself.
In TransDEM open the Map Tile client and click "Settings".
Set "Provider" to "2 Google Maps" and "Tile Type" to "Orthophoto". In the Tile Type group click "Edit".
In the URL composition dialog focus on group "URL part 1 - static". Change "Query prefix" to
Code:
kh/v=174
Click OK.
174 is the current version. Once it expires again, you will still be able to obtain a few tiles from your local cache, but no new tiles.
In this dialog there is also a sample URL at the very bottom. You can play around with it and also copy it to the clipboard and then paste it into an ordinary web browser. Increase v= until you get a positive result again.