unity3d - Unity 5.6.0f3 does not compile any c# script (System.RuntimeType not found) -

i downloaded latest unity version 5.6.0f3 , can't script compile.

steps:

1) open unity , create new project

2) add script component object in hierarchy

3) press play

=> error:

runtime critical type system.runtimetype not found

all compiler errors have fixed before can enter playmode! unityeditor.sceneview:showcompileerrornotification()

any idea can cause error? have no other scripts or assemblies in asset folder. it's complete new project 1 default script.

platform: windows 10 x64 (latest updates installed)

unity: 5.6.0f3 x64

ide: vs 2017 (but did not use yet, because default script fails compile)

edit:

unity 5.5.3 x64:

• assertion @ ..\mono\metadata\domain.c:718, condition `mono_defaults.runtimetype_class != 0' not met

using system.collections; using system.collections.generic; using unityengine;  public class test: monobehaviour {      // use initialization     void start () {      }      // update called once per frame     void update () {      } }