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SoMachine v4.3 - What do I do if I see Value cannot be null Parameter name: s?

Published date: 19 September 2019

Issue
In SoMachine v4.3, I am seeing a popup message:
"Value cannot be null.
Parameter name: s"


This error appears when I attempt to go online or download and won't let me download to my PLC. How do I get past it?

Product Line
SoMachine v4.1, SoMachine v4.2, SoMachine v4.3

Environment
Configuration Software in Windows

Cause
This message appears when a project has a PLC that is converted from one type to another and is related to PLC User Management (Security).

Resolution
Follow these steps:
1) Close the popup message by clicking on OK
2) From the Device Manager, double-click on the top node of your controller (default name is "MyController"). This will open up the "Controller selection" screen by default
3) Go to the "Users and Groups" tab
4) Under "Access protection", untick the checkbox next to "Enable user management" to disable security.
5) Tick the checkbox again to enable User Management again.

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