Sub package CsvHelper is included in both UiPath.System.Activities and UiPath.Excel.Activities.
It seems like this is causing error when appending a CSV, since the package is included twice with different version numbers.
An easy solution would be to remove CsvHelper from UiPath.Excel.Activities?
message: Append To CSV: Method not found: ‘Void CsvHelper.CsvWriter…ctor(System.IO.TextWriter)’.
level: Error