Problem when using force mode

I’m using a UR10 robot with the external FT sensor to activate force mode and the Polyscope version is 3.15.7.
When I write an URScript as follow and send it to robot port 30001 by socket. Nothing happens:
''def svt():
movel(p[0.65506,0.63983,0.18197,2.752,1.523,-0.096],a=0.6,v=0.05,t=0,r=0)
force_mode(tool_pose(), [0, 0, 1, 0, 0, 0], [0.0, 0.0, 30.0, 0.0, 0.0, 0.0], 2, [0.1, 0.1, 0.15, 0.17, 0.17, 0.17])
movel(p[0.63426,-0.30823,0.18010,2.784,1.451,-0.045],a=0.6,v=0.05,t=0,r=0)
end_force_mode()
stopl(5.0)
end

‘’’
But when I delete the line ‘end_force_mode()’, the robot starts to run the program. I’ve also tried the demo in Universal Robots - URScript: Dynamic Force Control ,where occurred the same problem: the robot can’t run the program when the line ‘end_force_mode()’ is not deleted.

I wonder why the robot seems not to understand this function and how can I disactivate the force mode in an URScript program.