What I had done is that I changed the name of the columns and then it throws this error.
1 Init State/1.13 PrepareDataToBeProcessed.xaml: The activity 'Assign Variables - Data of Hard Close Row - Monthly' cannot reference activity 'VisualBasicValue<Object>' because activity 'VisualBasicValue<Object>' is already referenced elsewhere in the workflow and that reference is not visible to activity 'Assign Variables - Data of Hard Close Row - Monthly'. In order for activity 'VisualBasicValue<Object>' to be visible to activity 'Assign Variables - Data of Hard Close Row - Monthly', it would have to be a child or imported child (but not an implementation child) of activity 'DynamicActivity'. Activity 'VisualBasicValue<Object>' is originally referenced by activity 'Assign Variables - Data of Hard Close Row - Monthly' and activity 'Assign Variables - Data of Hard Close Row - Monthly' is in the implementation of activity 'DynamicActivity'.
It seems the xaml file is corrupted. probably it’s necessary to modify it directly using text editor, or re-create the xaml file…
If you can share the file, we might be able to check it.