I am also running into this issue. The FSFileName is provided as pxRequestor.pyFilePath after uploading an Excel document through the FilePath control (PegaGadgets:8-01-01) with .pyFilePath listed as the target property of the control, and the TemplateRFB being passed in is present in the application. Both follow the same formats previously needed for the MSOParseExcelFile activity.
After running this activity with the above inputs and performing an Obj-Save on the page it was run on as well as the page provided for output (outputPageName), there is no data present. These pages are both of the same class. My tracer displays no warnings, errors, or fails when it is run during this process.
Where exactly on the clipboard would the parsed data be written to if not the outputPage or the page the activity was run on?