Hi Soriven,

you are posting on a very old thread; the last post before yours dates back to October 2014 and refers to a farily old version of Vuforia (Vuforia 3.x).

Using Vuforia 5.5.9, you should be able to run Play Mode on Windows with Unity 5.3.4, assuming Unity was correctly installed.

Do you see the same behaviour if you try and run the Image Targets 5.5.9 sample app in Unity 5.3.4 Play Mode  ?   

I'm having exactly the same thing on windows.

My PC is a very strong one.  Installed unity 32 bit as required since on the 64 bit version there is an error shown when playing.

the play mode runs for a while. I then try to detect the marker and it takes some time, but when it does, unity crashs and a bug report is being shown.

Did you manage to figure out what happens?

I am using Unity 5.3.4f1 with the latest Vuforia.

Please help

Are you referring to Frame Markers or Image Targets (there is no such notion of "marker" in Vuforia); in either case, I would recommend to try the samples first and see if you can reproduce the crash there (and if the samples are OK, try to compare your implementation with the sample to see if you are missing something).