In Foward Dynamics, "Time range to process" changes to "0 to 1" when changing a file in the Input section

[carmichaelong]

Steps to reproduce

1. Navigate to Tools --> Forward Dynamics
2. Change "Time range to process" to something other than "0 to 1"
3. Load either a) Tug_Of_War/Tug_of_War_Millard_controls.xml into "Controls" or b) Tug_Of_War/TugOfWar_Milliard_initial_states.sto into "Initial State"

Expected result

"Time range to process" does not change

Actual result

"Time range to process" changes to "0 to 1"

Environment and GUI version

W10 Pro, OpenSim 4.0-2018-10-01-76939822