Update README.md

Author: sinai-dev

README.md

@@ -20,6 +20,7 @@
 | Standalone | ✅ [link](https://github.com/sinai-dev/UnityExplorer/releases/latest/download/UnityExplorer.Standalone.Il2Cpp.zip) | ✅ [link](https://github.com/sinai-dev/UnityExplorer/releases/latest/download/UnityExplorer.Standalone.Mono.zip) | 
 
 ### Known issues
+* Issues with UnityEngine types in some 2020+ games - this is an issue with Unhollower, nothing I can do about it myself at the moment.
 * Any `MissingMethodException` or `NotSupportedException`: please report the issue and provide a copy of your mod loader log and/or Unity log.
 * The C# console may unexpectedly produce a GC Mark Overflow crash when calling certain outside methods. Not clear yet what is causing this, but it's being looked into.
 * In IL2CPP, some IEnumerable and IDictionary types may fail enumeration. Waiting for the Unhollower rewrite to address this any further.