Exception EString List Error dons le module SUMo.exe dons 00022A02

It happens even when the Debug Mode is ON or OFF. The same happens when I toggled the mode.
Then the following pop-up appears as I close the settings dialogue by clicking the OK key.

The error message says,
Error d’ application
Exception EString List Error dons le module SUMo.exe dons 00022A02.
Indices de list hors limits (-1).
Do you know how to prevent this? Please help.
