TypeError: y must be a float (transferring from vizard 3.0 to vizard 5.0)

[Melody]

viz.startlayer(viz.LINE_STRIP)
viz.vertexcolor(1,0,0)
mycurves1=viz.endlayer()
mycurves1.dynamic()
curvex=getposition()
curvey1=getforce1()
def curves1():
current_vertex=mycurves1.addVertex([curvex,curvey1,0],viz.ABS_GLOBAL)
mycurves1.setVertex(current_vertex, [curvex,curvey1,0],viz.ABS_GLOBAL)
current_vertex=mycurves1.addVertex([curvex,curvey1,0],viz.ABS_GLOBAL)
vizact.onsensordown(sensor,4,mycurves1.clearVertic es)

This is the part which result in error.