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    Type:Bug 
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    Resolution: Fixed
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    Priority:Major - P3 
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    Affects Version/s: None
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    Component/s: Aggregation Framework, Upgrade/Downgrade
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    None
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        Fully Compatible
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        ALL
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        Query 2019-06-03
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        None
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        None
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        None
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        None
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        None
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        None
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        None
These could cause issues with downgrade and/or replication in a mixed-version cluster.