DatabaseVersion doesn't exist in database entry { _id: \"db_wayee_env\", primary: \"shard2\", partitioned: false }

First ,the version is 3.6,and I upgraded to 4.0,there is no problem.Today I upgraded to 4.2 ,when I query the database ,it show the error.

Error: error: {
	"ok" : 0,
	"errmsg" : "DatabaseVersion doesn't exist in database entry { _id: \"db_wayee_env\", primary: \"shard2\", partitioned: false } despite the config server being in binary version 4.2 or later.",
	"code" : 1,
	"codeName" : "InternalError",
	"operationTime" : Timestamp(1596869996, 1),
	"$clusterTime" : {
		"clusterTime" : Timestamp(1596869996, 1),
		"signature" : {
			"hash" : BinData(0,"vCYWXny2iOfGYHrtK57jhIxQTys="),
			"keyId" : NumberLong("6802144151413456897")
		}
	}
}

how do I solve this problem?Thanks

Hi @xu_zhang,

Have you switched the FCV to 4.2 and restarted all mongos?

Please note the above is a mandatory step.

Best regards
Pavel