Quick answer: Unity Newtonsoft.Json deserialization failing in IL2CPP builds? Method metadata stripped - add Newtonsoft to link.xml or use compile-time serializer.

JSON parser throws 'cannot find constructor' in iOS build. Editor works.

Preserve Newtonsoft assembly

<assembly fullname="Newtonsoft.Json" preserve="all"/>

In link.xml. Library survives stripping.

Or use System.Text.Json with source-gen

Compile-time serializer; no reflection at runtime. AOT-safe by construction.

Avoid reflection in shipping code

Reflection + AOT + stripping = three independent failure modes. Eliminate at design time.

“Reflection-heavy libraries don't compose with aggressive stripping. Preserve or replace.”

If your game has heavy JSON usage, the source-gen replacement is worth the migration. Smaller; faster; AOT-safe.

Related reading