Error in creating new Collection
 The object reference is not set to an instance of the object.
 Type: System.NullReferenceException
 Stack: at mangoui.comnavtree.x7vulvsz8pv8voeq5ve (object)
 At mangoui.comnavtree.dbaddcollection _ click (objectsender, eventargse)

Looking for half a day always finds the answer:

History

MongoDBThere used to be only one storage engine calledMMAPv1,MongoDB3.0The introduction of makesmongodbThere are two engines:MMAPv1AndWiredTiger.

• MMAPv1: applicable to allMongoDBVersion,MongoDB3.0The default engine for

• WiredTiger: only supported64positionMongoDB

Reason

MongoDBIn3.2After the default iswiredTigerThe engine, andThe management software matches the previous engine, so it cannot be used and the memory engine must be reset.

Solve

• Switching storage engines

MongoDB can switch between the two engines. We can specify the engine type when creating the service.

mongod –storageEngine mmapv1 –dbpath D:\mongo\data