We have crashes too, but different. If you can repeat that, please use WinDbg to gain maximum information. You can then attach debugger to Filemaker process and filemaker staff will see more information about the error. Event Viewer in windows is other place where to look.Filemaker has no client logs!
Download this package and install Debugging tools. http://msdn.microsoft.com/en-us/windows/hardware/gg463009.aspx
FM12 seems to producing more crashes than we have used to be, from my point of view. I know, it can be caused with "bad" plugins or corrupt database, but it should not crash this way...