Bug description

I'm using messagepack for my project and I'm saving level's data with it.
after some work on project on desterilizing it fails with this error:
MessagePackSerializationException: Unexpected msgpack code 147 (fixarray) encountered.
it's working on another branch with the same file.

here's my code:
data = MessagePackSerializer.Deserialize<CellData[]>(cellsData);

• Version used:
• unity 2019.4
• Runtime: .Net core 3