Summary

When you insert a document into an encrypted collection, the safeContent field is automatically added. (This field is necessary for QE to work.) If you attempt to then find that document and let the driver automatically deserialize it to a POCO you've defined, the driver throws an exception:

Unhandled exception. System.FormatException: Element 'safeContent' does not match any field or property of class <your POCO class>.

I was able to avoid this error by adding the 
[BsonIgnoreExtraElements] attribute to my POCO class, but it would be nice if the driver were aware that it should ignore that field.

Motivation

Who is the affected end user?

Anyone using the C# driver for QE with POCOs

How does this affect the end user?

Throws an exception if the attribute is not added

How likely is it that this problem or use case will occur?

Assuming most users use POCOs, this is a main path error

If the problem does occur, what are the consequences and how severe are they?

The app doesn't work without the attribute

Is this ticket required by a downstream team?

No

Is this ticket only for tests?

No

Acceptance Criteria

Ideally, I wouldn't need to add this attribute to the class in order for QE to work with POCOs. If that's not possible, we can discuss documenting this requirement somewhere.