Exceptions: the above is valid for any project created with TAP Studio 20.12.xxxx or older. However, if your automation solution uses the excelDocument automation object (fully qualified name: MissionCritical.Automation.Excel.excelDocument, RPA, Version=1.4.0.0, Culture=neutral, PublicKeyToken=null), you will need to manually update all variables of this type to excelDocument type using the "Choose Type" option within the variables pane from TAP Studio.