Unregistered Expression Editor - Cannot find an expression editor named 'C#'


I have received an error as mentioned in Subject of this topic.
It is when I downloaded the sample program in the Debugging course of the RPA Developer Production Readiness Essentials training.
I have always chosen VB instead of C# to create programs in UiStudio.
Can anyone please advise me how to fix this error?

this is something new
can you open that workflow so that we could see where we get this error and share that screenshot if possible
Cheers @Divik

Thanks - I shared that screenshot in my previous message.
It is from the “Main” sequence in the “Main.xaml” file attached below.

I have also attached the invoked workflows to this reply.

Main.xaml (7.4 KB)

Cleanup.xaml (6.8 KB)

CopyAndUpdate.xaml (10.4 KB)

I’m having the same error, a co worker of mine came to me with the prob, at first the project worked, then suddently he dosn’t know why when trying to open it he got an error saying c# is not supported. When opening the project.json I could see the expressionlanguage was set to c#, changing it back to visual basic, I was able to open it, but getting the above error

How do you set the expression language back to visual basic?

I opened the project.json in notepad and changed it there

kindly have a view on this thread pls

Cheers @Daniel_D @Divik

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Thanks. So I opened up the JSON file and changed the expression language to “VisualBasic”.
That made it so I can open up the xaml file.


But my understanding from the thread is that the “Unregistered Expression Error” for activities within the xaml file cannot be fixed at the moment. This is due to file originally being created in C#, which is currently not supported in the current 2019.10.10 version of UiStudio.


So if I want to update the activities, I believe I need to correct them manually.

@Divik I opened up the JSON file and changed the expression language to “VisualBasic”.Still, I got the error. Here I attached screenshots.


Thanks. I think even then you have to update the activities manually in the XAML file.
But yes changing the expression editor to VisualBasic in the JSON file is necessary when receiving UiStudio projects in C#. :grinning:

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