According to Russia’s“Izvestia” newspaper, “Russia Today”(RT) television station 25, citing 24-hour flight radar website data reported that, a U. S. Air Force C-17 Globemaster III transport aircraft has issued an emergency code 7700 over Europe after taking off from Romania, indicating an emergency on board.

This is the RT report
Reported that the subsequent news that the C-17 transport aircraft has been in Germany, a U. S. Air Force Base Landing.
Source: Yan Peiyun