The Navigator VI is notoriously flakey. Mine did that, before displaying other signs of demonic possession. I returned it to BMW for a full refund.
But try the following:
1. DO NOT do a full hard reset, unless you have access to a PC and can save your routes / favourites. You will lose all your data.
2. Shut the device down fully by holding the on-off switch down, then saying Yes to the prompt. Then restart again. Does this kick it into life again?
3. If the answer to point two is yes, then for now at least, you are on your way.
4. If the answer to point two is no, try removing the battery, as suggested above.
5. Does it work now?
6. If the answer is no….. the only realistic solution is to:
A. Buy a map, a sheet or two of paper and a pencil. Route planning old style. It does work. This is probably the easiest solution.
B. Assuming you do not have your phone (as so many do) mounted already on your bike. Go to a BMW dealership (or use Amazon for a delivery in Germany) and buy the Connect cradle. At least you’ll be able to use a reasonably modern phone as a navigation device, assuming you have one. You could then go the full hog and create your routes in say MyRoute on your phone (you may have them there anyway) and run them from you phone via the MYRoute Navigation app or via the BMW Connect app. In short, find the easiest method to use your phone.
Or buy from them a fresh Nav VI (better still a Nav V, if they have one) and Bluetooth your routes across.
C. Go to a store (or Amazon) selling an XT and install it onto your bike. Then Bluetooth the routes from your Navigator VI to the XT.
D. See if you can find someone on EBay selling a Navigator V or IV (or similar Garmin models) and have them send it to you in Germany.
PS Some of these suggestions might require you to be in Germany for a day or two at least. Though if you have a reliable forward address or two, you could consider using those.