When I create a ChangeStream (using Collection.watch() ) and then drop the collection,

I get this stacktrace in 4.2.1 & 4.2.2 - no exception is present in 4.2.0:

ERROR reactor.core.publisher.Operators - Operator called default onErrorDropped
reactor.core.Exceptions$ErrorCallbackNotImplemented: java.lang.IllegalStateException: state should be: open
Caused by: java.lang.IllegalStateException: state should be: open
at com.mongodb.assertions.Assertions.isTrue(Assertions.java:72)
at com.mongodb.internal.operation.AsyncQueryBatchCursor.setBatchSize(AsyncQueryBatchCursor.java:149)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor.setBatchSize(AsyncChangeStreamBatchCursor.java:105)
at com.mongodb.reactivestreams.client.internal.BatchCursor.setBatchSize(BatchCursor.java:43)
at com.mongodb.reactivestreams.client.internal.BatchCursorFlux.recurseCursor(BatchCursorFlux.java:82)
at com.mongodb.reactivestreams.client.internal.BatchCursorFlux.lambda$recurseCursor$4(BatchCursorFlux.java:101)
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onComplete(MonoPeekTerminal.java:289)
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onComplete(MonoPeekTerminal.java:299)
at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onComplete(FluxPeekFuseable.java:940)
at reactor.core.publisher.MonoCreate$DefaultMonoSink.success(MonoCreate.java:133)
at com.mongodb.reactivestreams.client.internal.MongoOperationPublisher.lambda$sinkToCallback$30(MongoOperationPublisher.java:548)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor$3.onResult(AsyncChangeStreamBatchCursor.java:169)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor$3.onResult(AsyncChangeStreamBatchCursor.java:145)
at com.mongodb.internal.async.ErrorHandlingResultCallback.onResult(ErrorHandlingResultCallback.java:48)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor$4.onResult(AsyncChangeStreamBatchCursor.java:190)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor$4.onResult(AsyncChangeStreamBatchCursor.java:186)
at com.mongodb.internal.operation.AsyncQueryBatchCursor.next(AsyncQueryBatchCursor.java:213)
at com.mongodb.internal.operation.AsyncQueryBatchCursor.next(AsyncQueryBatchCursor.java:138)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor$1.apply(AsyncChangeStreamBatchCursor.java:74)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor.resumeableOperation(AsyncChangeStreamBatchCursor.java:186)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor.next(AsyncChangeStreamBatchCursor.java:70)
at com.mongodb.reactivestreams.client.internal.BatchCursor.lambda$next$0(BatchCursor.java:35)
at reactor.core.publisher.MonoCreate.subscribe(MonoCreate.java:57)
at reactor.core.publisher.Mono.subscribe(Mono.java:4046)
at reactor.core.publisher.Mono.subscribeWith(Mono.java:4161)
at reactor.core.publisher.Mono.subscribe(Mono.java:3878)
at com.mongodb.reactivestreams.client.internal.BatchCursorFlux.recurseCursor(BatchCursorFlux.java:104)
at com.mongodb.reactivestreams.client.internal.BatchCursorFlux.lambda$recurseCursor$4(BatchCursorFlux.java:101)
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onNext(MonoPeekTerminal.java:171)
at reactor.core.publisher.MonoPeekTerminal$MonoTerminalPeekSubscriber.onNext(MonoPeekTerminal.java:180)
at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onNext(FluxPeekFuseable.java:854)
at reactor.core.publisher.MonoCreate$DefaultMonoSink.success(MonoCreate.java:160)
at com.mongodb.reactivestreams.client.internal.MongoOperationPublisher.lambda$sinkToCallback$30(MongoOperationPublisher.java:550)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor$3.onResult(AsyncChangeStreamBatchCursor.java:167)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor$3.onResult(AsyncChangeStreamBatchCursor.java:145)
at com.mongodb.internal.async.ErrorHandlingResultCallback.onResult(ErrorHandlingResultCallback.java:48)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor$4.onResult(AsyncChangeStreamBatchCursor.java:190)
at com.mongodb.internal.operation.AsyncChangeStreamBatchCursor$4.onResult(AsyncChangeStreamBatchCursor.java:186)
at com.mongodb.internal.async.ErrorHandlingResultCallback.onResult(ErrorHandlingResultCallback.java:48)
at com.mongodb.internal.operation.AsyncQueryBatchCursor.handleGetMoreQueryResult(AsyncQueryBatchCursor.java:367)
at com.mongodb.internal.operation.AsyncQueryBatchCursor.access$600(AsyncQueryBatchCursor.java:56)
at com.mongodb.internal.operation.AsyncQueryBatchCursor$CommandResultSingleResultCallback.onResult(AsyncQueryBatchCursor.java:399)
at com.mongodb.internal.operation.AsyncQueryBatchCursor$CommandResultSingleResultCallback.onResult(AsyncQueryBatchCursor.java:372)
at com.mongodb.internal.async.ErrorHandlingResultCallback.onResult(ErrorHandlingResultCallback.java:48)
at com.mongodb.internal.connection.DefaultServer$DefaultServerProtocolExecutor$2.onResult(DefaultServer.java:286)
at com.mongodb.internal.async.ErrorHandlingResultCallback.onResult(ErrorHandlingResultCallback.java:48)
at com.mongodb.internal.connection.CommandProtocolImpl$1.onResult(CommandProtocolImpl.java:84)
at com.mongodb.internal.connection.DefaultConnectionPool$PooledConnection$2.onResult(DefaultConnectionPool.java:530)
at com.mongodb.internal.connection.UsageTrackingInternalConnection$2.onResult(UsageTrackingInternalConnection.java:142)
at com.mongodb.internal.async.ErrorHandlingResultCallback.onResult(ErrorHandlingResultCallback.java:48)
at com.mongodb.internal.connection.InternalStreamConnection$2$1.onResult(InternalStreamConnection.java:462)
at com.mongodb.internal.connection.InternalStreamConnection$2$1.onResult(InternalStreamConnection.java:439)
at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback$MessageCallback.onResult(InternalStreamConnection.java:744)
at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback$MessageCallback.onResult(InternalStreamConnection.java:711)
at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:581)
at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:578)
at com.mongodb.internal.connection.AsynchronousChannelStream$BasicCompletionHandler.completed(AsynchronousChannelStream.java:250)
at com.mongodb.internal.connection.AsynchronousChannelStream$BasicCompletionHandler.completed(AsynchronousChannelStream.java:233)
at sun.nio.ch.Invoker.invokeUnchecked(Invoker.java:126)
at sun.nio.ch.Invoker.invokeDirect(Invoker.java:157)
at sun.nio.ch.UnixAsynchronousSocketChannelImpl.implRead(UnixAsynchronousSocketChannelImpl.java:553)
at sun.nio.ch.AsynchronousSocketChannelImpl.read(AsynchronousSocketChannelImpl.java:276)
at sun.nio.ch.AsynchronousSocketChannelImpl.read(AsynchronousSocketChannelImpl.java:297)
at com.mongodb.internal.connection.AsynchronousSocketChannelStream$AsynchronousSocketChannelAdapter.read(AsynchronousSocketChannelStream.java:144)
at com.mongodb.internal.connection.AsynchronousChannelStream.readAsync(AsynchronousChannelStream.java:118)
at com.mongodb.internal.connection.AsynchronousChannelStream.readAsync(AsynchronousChannelStream.java:107)
at com.mongodb.internal.connection.InternalStreamConnection.readAsync(InternalStreamConnection.java:578)
at com.mongodb.internal.connection.InternalStreamConnection.access$1100(InternalStreamConnection.java:78)
at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback.onResult(InternalStreamConnection.java:701)
at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback.onResult(InternalStreamConnection.java:686)
at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:581)
at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:578)
at com.mongodb.internal.connection.AsynchronousChannelStream$BasicCompletionHandler.completed(AsynchronousChannelStream.java:250)
at com.mongodb.internal.connection.AsynchronousChannelStream$BasicCompletionHandler.completed(AsynchronousChannelStream.java:233)
at sun.nio.ch.Invoker.invokeUnchecked(Invoker.java:126)
at sun.nio.ch.UnixAsynchronousSocketChannelImpl.finishRead(UnixAsynchronousSocketChannelImpl.java:430)
at sun.nio.ch.UnixAsynchronousSocketChannelImpl.finish(UnixAsynchronousSocketChannelImpl.java:191)
at sun.nio.ch.UnixAsynchronousSocketChannelImpl.onEvent(UnixAsynchronousSocketChannelImpl.java:213)
at sun.nio.ch.EPollPort$EventHandlerTask.run(EPollPort.java:293)
at sun.nio.ch.AsynchronousChannelGroupImpl$1.run(AsynchronousChannelGroupImpl.java:112)