simtk.org

Hello,
I'm stumped by what is probably a simple error somewhere in a very basic inverse dynamics + static optimisation simulation I'm trying.
I add .mot kinematics to a model, add .mot GRF associated motion data (all seems fine to that point), then give those GRFs settings for expressed in/applied to etc.; and get this error (cannot proceed further; follow-on analyses fail):

java.lang.NullPointerException
at org.opensim.view.motions.MotionDisplayer.bindExperimentalDataObjectToVisualizerObjectKeepHandle(MotionDisplayer.java:487)
at org.opensim.view.motions.MotionDisplayer.updateMotionObjects(MotionDisplayer.java:729)
at org.opensim.view.experimentaldata.AnnotatedMotion.updateMotionDisplayer(AnnotatedMotion.java:490)
at org.opensim.view.experimentaldata.MotionEditMotionObjectsAction$1.windowClosed(MotionEditMotionObjectsAction.java:70)
at java.awt.AWTEventMulticaster.windowClosed(AWTEventMulticaster.java:360)
at java.awt.Window.processWindowEvent(Window.java:2057)
at javax.swing.JDialog.processWindowEvent(JDialog.java:683)
at java.awt.Window.processEvent(Window.java:2013)
at java.awt.Component.dispatchEventImpl(Component.java:4889)
at java.awt.Container.dispatchEventImpl(Container.java:2297)
at java.awt.Window.dispatchEventImpl(Window.java:2746)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:760)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:84)
at java.awt.EventQueue$4.run(EventQueue.java:733)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:730)
at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:136)
[catch] at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

At first I thought this was just a visualisation problem but it seems to be something more fundamental that is an inverse dynamics input problem?