What i did is i went to drive c then program files, Google, Google SketchUp, Then plugins and deledted everything for SkeatchyPhysics. Then i downloaded it again. Then i made a symple cube and put a motor on it and made it run it was fine. Then i saves it as my test and closed sketchup for about 5 to 10 seconds and then reopend SketchUp. Opened my test again and ran it. Ran perfectly. When before it used to close after i opened it the second time and try to run it. Hope it works for someone

When I 'open' a file that had perfectly-running animation when I 'saved' it, I nearly always get a 'bugsplat' as soon as I click 'play'. Thereafter, no amount of elimination and simplification will restore the model to any form of functioning animation until even an empty workspace crashes when I press 'play'. I'm using SU8 with SP3.2 on Windows 7 and most of my models are engines of various types. I've reloaded SU8 (several times), tried saving as SU7, tried 3D warehouse models and updated the graphics card. Still the problem continues! Suggestions earnestly requested!