modify/create Free Text Invoice

I’m not sure how to modify the existing report, as it uses a class as a data source that is deeply embedded/tied to the FreeTextInvoiceTmp table.  I thought to try and create a new FTI template per this link msdn.microsoft.com/.../hh209275.aspx, but my AX client crashes on me when I click the AR, Setup, Free text invoice templates.  I also thought about creating a new report.  Can I get some guidance on how this should be done?  TIA, Steve