getInverseKinematics unable to find a solution & RTDE control script not running


I am using version 5.12 of the offline URSim software for the UR10 (on a Linux Ubuntu 20.04) with my own code, and everything works properly when I run a script that is controlling the robot. However, whenever I try to use getInverseKinematics() in my code, I get the following error message:

RTDEControlInterface: RTDE control script is not running!

Here is an example of code I used to run some tests:

>>>import rtde_control
>>>import rtde_receive
>>>HOST = ""
>>>GOAL_POS = [-0.18507570121045797, -0.43755157063468963, 0.21101969081827837, -0.06998478570599498, -3.0949971695297402, 0.10056260631290592]
>>>control = rtde_control.RTDEControlInterface(HOST)
>>>GOAL_COORD = control.getForwardKinematics(GOAL_POS)
[-1.1954591039150162, 0.23226171709176066, 2.030813827294871, -0.664507533790512, -2.0517813952231, -2.1201251853851155]
>>>GOAL_POS = control.getInverseKinematics(GOAL_COORD)
RTDEControlInterface: RTDE control script is not running!

In addition to the error message, I also see the popup in the simulator that says: "The robot cannot reach the requested pose. Script function get_inverse_kin is unable to find a solution.

This is curious to me because I have obtained the tool position GOAL_COORD directly from a joint angle position (GOAL_POS) that was valid, and therefore, I would be expecting that converting back an forth would work.

Did I miss anything?