thank you for the link! my saturday is saved.
it worked!
here is the solution, in case anyone stumbles over this post: (copied from the above mentioned thread):
The solution is:
-- Switch to PlayMaker Nacl version, which has its network support removed. Go to the PlayMaker/Versions folder and install PlaymakerNACL.unitypackage
-- Remove all networking actions (in PlayMaker/Actions/networking)
1: you have PlayMaker Nacl installed
2: you have micro mscorlib stripping selected
3: you have an GameObject with a GUITexture /*or in my case: "GUIText"*/ component
4: you have an fsm with a "Set Property" action setting a property of that GUITexture/GUIText
5: create a link.xml under your "Assets/" folder with the following content:
<linker>
<assembly fullname="UnityEngine">
<type fullname="UnityEngine.GUIText" preserve="all"/>
</assembly>
</linker>