Object Reference error in invoke code workflowinvoker.invoke method

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1

I am trying to invoke log message activity in invoke code but getting object reference error at workflowinvoker.invoke method
Code inside invoke code:
Dim logMessage As UiPath.Core.Activities.LogMessage = New UiPath.Core.Activities.LogMessage()
logMessage.Level = New InArgument(Of LogLevel)(LogLevel.Error)
logMessage.Message = New InArgument(Of Object)(“abcd”)
Dim logInvoker As System.Activities.WorkflowInvoker = New System.Activities.WorkflowInvoker(logMessage)
logInvoker.Invoke()

1 Like
2

@Nirav_Gajera

Try changing lomessage variable to something else

Cheers

3

Object Reference not set to an instance of an object means the variable is not initialized (it’s null). This means your calling workflow does not have a value for that argument.

4

The same code is working fine inside the library but when I tried to use the same in the new project, it is throwing object reference error at invoke method. System.activities package is also same and imports are also matching so I am wandering what could be the issue here

5

@Nirav_Gajera

So are you trying to use that created log mesage method in the workflow?

If so it might not work as they are two different instances also

Cheers

6

No, I am using same pice of code but it works inside the library which is not connected to any of the project. Now I have to use it in entirely new project, so I did the same by dragging invoke code activity and writting same lines but it is not working in this new project. I am quite aware what object reference is and here object is initialised but somehow object reference error at invoke method.

7

Log message object is initialised and has all the arguments set up correctly, I am not sure why object reference error at invoke method. Also it is working fine in other independent Library so I am just wandering if it is import issue or something like that but not sure as imports are also matching and package is also matching with that library.

8

Check and see if you accidentally have a variable with the same name as the argument. I’ve done this and pulled my hair out for a while trying to find the problem.

Another problem may be that you have the default of a variable/argument that includes another variable/argument. For example:

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That will cause an Object Reference error.

9

It is also not the case, I am sharing the code block that I am using inside Invoke code. Any suggestion is appreciated.

	Try 
		Dim logMessage1 As UiPath.Core.Activities.LogMessage = New UiPath.Core.Activities.LogMessage()
		logMessage1.Level = New InArgument(Of LogLevel)(LogLevel.Error)
		logMessage1.Message = New InArgument(Of Object)("ABC")
		Dim logInvoker As WorkflowInvoker = New WorkflowInvoker(logMessage1)
		logInvoker.Invoke()
	Catch e As Exception
		Console.WriteLine(e.Message)
	End Try
10

+1 - same problem here, Studio 2024.10.1, UiPath.System.Activities v24.10.3