I have tried all of the above: installed SU7 with sketchyphysics plugin, saved the file in 7-format and tried to run it in 7. No other plugins installed in this version. But it crashed. So I started to design again from scratch in 8.0, started a new file and when I start to run the simulation, it crashes. It does not happen in other projects so I guess it has something to do with the way I designed the object. https://drive.google.com/file/d/0BzgoaQHxd3uRdnE5Z2pYR21KSDQ/edit?usp=sharing [image: J7co_swingingdoor2.jpg] I am trying to design a simple Torggler-door with one rod: http://torggler.co.at/main/systems.html