On a MacBook Air running the latest El Capitan public beta (10.11.5) we're seeing very high CPU utilization (25 to 100+%) by the bird process.

We're seeing a number of errors (rather than a persistent one) some of the more common ones are:

[ERROR] 57226.692 [2016-05-07 22:23:40.422] upload/com.apple.CloudDocs     sync.transfer        BRCTransferBatchOperation.m:222
        failed uploading 1 items (178 bytes) in com.apple.CloudDocs: <CKError 0x7f8a6bf3ba40: "Partial Failure" (2/1011); "Failed to modify some records"; partial errors: {
                documentContent/817537A5-F0B6-4F4C-A7DB-C4C6204751D6:(com.apple.CloudDocs:__defaultOwner__) = <CKError 0x7f8a6e021b60: "Asset File Modified" (17/3003); "generation counter mismatch (4 != 3)">

[ERROR] 58828.969 [2016-05-07 22:50:22.699] NSXPCConnection.user.580       xpc.client                 BRCXPCClient.m:808
        nil error: <NSError:0x7f8a6be86540(NSPOSIXErrorDomain:1) - {
            NSDescription = "can't create container for (null)";

The resulting CPU utilization makes the machine almost unusable, any suggestions for a solution short of turning off iCloud drive?


1 Answer 1


I have actually had decent luck with Apple online support when this hit one of our Macs. We went through several things like restart and sign out and then had to enable debug logs with a profile and sent in logs.

It got resolved shortly. Not sure if they fixed it server side or an update that came out a day later resolved it for me. I didn’t have to change any files on my side.

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