Hi, This time, it appears to be because a "status" document doesn't have a "txn-revno" field : juju:PRIMARY> db.statuses.find({ _id: { $regex: "ksplice/31#charm" } }).pretty() { "_id" : "0b399859-692f-4e41-8f6d-c3a837cd26c3:u#ksplice/31#charm", "env-uuid" : "0b399859-692f-4e41-8f6d-c3a837cd26c3", "status" : "unknown", "statusdata" : { }, "statusinfo" : "", "txn-queue" : [ "5855f8181c56b63028334e84_66b7dbac", "58613aac1c56b670e01053dd_d6947399", "5865225a1c56b670e01bcf58_949b14d0", "5865e7ff1c56b670e01e1457_62b06131", "586b8f841c56b670e02eb517_35ffc19a" ] } Let's look at the txn-queue : juju:PRIMARY> db.txns.find({ _id: ObjectId('5855f8181c56b63028334e84') }).pretty() { "_id" : ObjectId("5855f8181c56b63028334e84"), "n" : "165ddd7e", "o" : [ { "c" : "statuses", "d" : "0b399859-692f-4e41-8f6d-c3a837cd26c3:u#ksplice/31#charm", "a" : { "txn-revno" : NumberLong(0) }, "u" : { "$set" : { "env-uuid" : "0b399859-692f-4e41-8f6d-c3a837cd26c3", "status" : "active", "statusinfo" : "Effective kernel 3.13.0-105-generic", "statusdata" : { }, "updated" : NumberLong("1482029080376315530"), "neverset" : false } } } ], "s" : 5 } As you can see, the only assertion is that txn-revno == 0, which I guess isn't the case because there no "txn-revno" field ? This causes the state to be set to 5 ("aborted"). And causes the status update to fail. The other queued txn are similar, e.g. : juju:PRIMARY> db.txns.find({ _id: ObjectId('58613aac1c56b670e01053dd') }).pretty() { "_id" : ObjectId("58613aac1c56b670e01053dd"), "n" : "189c1ad6", "o" : [ { "c" : "statuses", "d" : "0b399859-692f-4e41-8f6d-c3a837cd26c3:u#ksplice/31#charm", "a" : { "txn-revno" : NumberLong(0) }, "u" : { "$set" : { "env-uuid" : "0b399859-692f-4e41-8f6d-c3a837cd26c3", "status" : "active", "statusinfo" : "Effective kernel 3.13.0-106-generic", "statusdata" : { }, "updated" : NumberLong("1482767020431622924"), "neverset" : false } } } ], "s" : 5 } Example of a status document which works - you can see the txn-revno field : juju:PRIMARY> db.statuses.find({ _id: { $regex: "ksplice/45#charm" } }).pretty() { "_id" : "0b399859-692f-4e41-8f6d-c3a837cd26c3:u#ksplice/45#charm", "env-uuid" : "0b399859-692f-4e41-8f6d-c3a837cd26c3", "neverset" : false, "status" : "active", "statusdata" : { }, "statusinfo" : "Effective kernel 3.13.0-106-generic", "txn-queue" : [ "586f68f61c56b6227e004006_17264e09" ], "txn-revno" : NumberLong(6194), "updated" : NumberLong("1483696374166671919") } What should we do here ? Thanks