Why am I getting the error "The serializer for field ... must implement IBsonArraySerializer" when using AnyIn?

Question

I declare a Filter in c# by mongodb like this:

var filters = new List<FilterDefinition<Message>>
if (!area.Equals(""))
filters.Add(Builders<Message>.Filter.Eq("Domain", area));

and work perfectly when area is a single string for example 1. but I want area is 1,2,5,55,this filter work. In order to this I have changed my filter to this:

filters.Add(Builders<Message>.Filter.AnyIn(x => x.Domain, area));

according this suggestion

but I got this error :

The serializer for field 'Domain' must implement IBsonArraySerializer and provide item serialization info.

Why am I getting this error and how can I fix it?

I have seen this post but nobody do not answer to this post.

Answer 1

If I have understood the question correctly, you shouyld be using the $in query:

   filters.Add(Builders<Message>.Filter.In("Domain", new List<int>() { a1, a2 }));