[ SOLVED ] Ignition error source

Hi, I got this error:

com.inductiveautomation.ignition.client.gateway_interface.GatewayException: com.inductiveautomation.ignition.client.gateway_interface.GatewayException: java.lang.IllegalArgumentException: User Source "Operador" not found.

	caused by GatewayException: java.lang.IllegalArgumentException: User Source "Operador" not found.
	caused by GatewayFunctionException: java.lang.IllegalArgumentException: User Source "Operador" not found.

Can someone help me please?

This happen when my PLC is off

Without the rest of the stack trace, there's no way to help you identify the source of this error.

that was all the stack trace but I found what was, when says that can't found the user source is because in my project, there is a second instance of desktop and can't open more than one instance.