Error 2501 Outputto action cancelled

When trying to use the "Docmd.OutputTo" command in Access to export a report to a PDF file, we started getting error 2501, Outputto Action Cancelled.

The code seems to be really picky. If you Google this error message, you get all kinds of suggestions. This is what worked for us:

Dim ReportName As String

ReportName = "rptPrefundExceptions"

DoCmd.OpenReport ReportName, acViewPreview, , "LoanID=" & Me.LoanID

DoCmd.SelectObject acReport, ReportName

DoCmd.OutputTo acOutputReport, ReportName, acFormatPDF, CalculateFileLocation & ReportName & ".pdf", 0, , , acExportQualityPrint


Note: calculatefilelocation is a subroutine that dynamically calculates the right folder for each customer associated with the report.