We have upgraded to Play 2.7.0 recently and use play2-reactivemongo version 0.16.2 with reactivemongo 0.16.3. We use reactivemongo-shaded-native but also tried
Do ensure that your user has access to the Database you are trying to connect. I had same problem. I was testing with one user which belonged to other Database. Later I created one user for my Database then tested and it works fine.