Unknown index format

Hi there Unity community!

I'm getting quite a lot of these errors when I try to create a build:

Code (CSharp):

1. Unknown index format
2. UnityEditor.BuildPipeline:BuildPlayerInternalNoCheck()
3. UnityEditor.DefaultBuildMethods:BuildPlayer(BuildPlayerOptions) (at C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:172)
4. UnityEditor.BuildPlayerWindow:CallBuildMethods(Boolean, BuildOptions) (at C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:96)
5. UnityEditor.BuildPlayerWindow:BuildPlayerAndRun(Boolean) (at C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindow.cs:130)
6. UnityEditor.BuildPlayerWindow:GUIBuildButtons(IBuildWindowExtension, Boolean, Boolean, Boolean, BuildPlatform) (at C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindow.cs:926)
7. UnityEditor.BuildPlayerWindow:ShowBuildTargetSettings() (at C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindow.cs:798)
8. UnityEditor.BuildPlayerWindow:OnGUI() (at C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindow.cs:367)
9. System.Reflection.MonoMethod:InternalInvoke()
10. System.Reflection.MonoMethod:Invoke(Object, BindingFlags, Binder, Object[], CultureInfo)
11. System.Reflection.MethodBase:Invoke(Object, Object[])
12. UnityEditor.HostView:Invoke(String, Object) (at C:\buildslave\unity\build\Editor\Mono\HostView.cs:357)
13. UnityEditor.HostView:Invoke(String) (at C:\buildslave\unity\build\Editor\Mono\HostView.cs:351)
14. UnityEditor.HostView:OldOnGUI() (at C:\buildslave\unity\build\Editor\Mono\HostView.cs:147)
15. UnityEngine.UIElements.IMGUIContainer:DoOnGUI(Event, Matrix4x4, Rect, Boolean) (at C:\buildslave\unity\build\Modules\UIElements\IMGUIContainer.cs:275)
16. UnityEngine.UIElements.IMGUIContainer:HandleIMGUIEvent(Event, Matrix4x4, Rect) (at C:\buildslave\unity\build\Modules\UIElements\IMGUIContainer.cs:478)
17. UnityEngine.UIElements.IMGUIContainer:HandleIMGUIEvent(Event) (at C:\buildslave\unity\build\Modules\UIElements\IMGUIContainer.cs:461)
18. UnityEngine.UIElements.IMGUIContainer:HandleEvent(EventBase) (at C:\buildslave\unity\build\Modules\UIElements\IMGUIContainer.cs:441)
19. UnityEngine.UIElements.MouseCaptureDispatchingStrategy:DispatchEvent(EventBase, IPanel) (at C:\buildslave\unity\build\Modules\UIElements\Events\MouseCaptureDispatchingStrategy.cs:84)
20. UnityEngine.UIElements.EventDispatcher:ProcessEvent(EventBase, IPanel) (at C:\buildslave\unity\build\Modules\UIElements\EventDispatcher.cs:280)
21. UnityEngine.UIElements.EventDispatcher:Dispatch(EventBase, IPanel, DispatchMode) (at C:\buildslave\unity\build\Modules\UIElements\EventDispatcher.cs:156)
22. UnityEngine.UIElements.BaseVisualElementPanel:SendEvent(EventBase, DispatchMode) (at C:\buildslave\unity\build\Modules\UIElements\Panel.cs:189)
23. UnityEngine.UIElements.UIElementsUtility:DoDispatch(BaseVisualElementPanel) (at C:\buildslave\unity\build\Modules\UIElements\UIElementsUtility.cs:250)
24. UnityEngine.UIElements.UIElementsUtility:ProcessEvent(Int32, IntPtr) (at C:\buildslave\unity\build\Modules\UIElements\UIElementsUtility.cs:68)
25. UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr) (at C:\buildslave\unity\build\Modules\IMGUI\GUIUtility.cs:179)
26.  
27. [C:\buildslave\unity\build\Runtime/Graphics/Mesh/CompressedMesh.cpp line 489]
28. (Filename: C:/buildslave/unity/build/Editor/Mono/BuildPlayerWindowBuildMethods.cs Line: 172)

I'm trying to build with 2019.1.0b2.
Happens multiple times while its processing the single scenes.
Any idea where to look?
Has it something to do with compressed Meshes?

Thanks for any hints!

 

Just figured out that it only happens with console builds. I will try my luck in the specific platform forum, since this seams to be related to their platform.