The bad interaction of collation and Symbol described by SERVER-27195 can cause indexes to be in an inconsistent state. Until we have a complete fix in place, we should prevent insertion of Symbol data which would be indexed with a non-simple collation. This additional restriction will apply only to new v:2 indexes with a non-simple collation.
- is related to
SERVER-27195 Symbol BSON type compares incorrectly with String when the collation is non-simple