What causes "PrintTicket was already committed." in dotnet/wpf?

Set PrintTicket exactly once per page reader, before Commit()ing the page.

dotnet/wpf · error · XpsPackagingException

PrintTicket was already committed.

Error message

PrintTicket was already committed.

What it means

XpsPackagingException thrown from the PrintTicket setter of XpsFixedPageReaderWriter when PrintTicket is set a second time after it has already been committed to the package. The XPS writer model allows a page's PrintTicket to be assigned exactly once; after commit it is written as a part and the assignment is immutable. This enforces package consistency between the page and its ticket part.

Solutions

Set PrintTicket exactly once per page reader, before Commit()ing the page.
If the ticket must change, create a new page (or a new document) and write it with the corrected ticket instead of reassigning.
Restructure code so the final ticket is computed before the first assignment (e.g. resolve defaults up front).
Track commitment state in your own code (bool ticketSet) to guard reassignment.
Wrap in try-catch for XpsPackagingException to detect double-commit during batch generation.

Example fix

// before
pageWriter.PrintTicket = defaultTicket;
if (userOverride != null) pageWriter.PrintTicket = userOverride; // throws
// after
PrintTicket final = userOverride ?? defaultTicket;
pageWriter.PrintTicket = final; // set once
pageWriter.Commit();

Defensive patterns

Strategy: validation

Validate before calling

// Guard before assigning
bool canSetTicket = true; // track locally
if (ticketAlreadySet.ContainsKey(pageWriter))
    throw new InvalidOperationException("PrintTicket already committed for this page");
// else assign once and record
pageWriter.PrintTicket = ticket;
ticketAlreadySet[pageWriter] = true;

Try / catch

try
{
    pageWriter.PrintTicket = finalTicket;
}
catch (XpsPackagingException ex) when (ex.Message.Contains("already committed"))
{
    log.Warn("PrintTicket reassignment ignored; first ticket retained.");
}

Prevention

Assign PrintTicket exactly once per page, computing the final value before the first set.
Centralize ticket assignment in a single SetPageTicket helper that tracks state.
Never set the ticket in retry loops; recreate the page on retry instead.
Commit pages only after the ticket is final.

When it happens

Trigger: Assigning the PrintTicket property twice on an IXpsFixedPageReaderWriter where the first assignment completed the commit — typically pageReader.PrintTicket = ticket; ...; pageReader.PrintTicket = otherTicket; while writing an XPS document.

Common situations: Code paths that retry page writing and reassign the ticket on a retry; loops that set defaults for all pages and then set page-specific tickets; frameworks that set a ticket per-property-update.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/c8c7f797f1de9247. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/ReachFramework/Packaging/XpsFixedPageReaderWriter.cs:509

        /// <exception cref="SR.ReachPackaging_PrintTicketAlreadyCommitted">part is null.</exception>
        /// <exception cref="SR.ReachPackaging_NotAPrintTicket">part is null.</exception>
        public PrintTicket PrintTicket
        {
            get
            {
                if( _printTicket == null )
                {
                    _printTicket = CurrentXpsManager.EnsurePrintTicket( Uri );
                }
                return _printTicket;
            }
            set
            {
                if(value != null)
                {
                    if (_isPrintTicketCommitted)
                    {
                        throw new XpsPackagingException(SR.ReachPackaging_PrintTicketAlreadyCommitted);
                    }
                    if (!value.GetType().Equals(typeof(PrintTicket)))
                    {
                        throw new XpsPackagingException(SR.ReachPackaging_NotAPrintTicket);
                    }

                    _printTicket = value.Clone();
                }
                else
                {
                    _printTicket = null;
                }
            }
        }

        /// <summary>
        /// Gets a reference to the XmlWriter for the Metro part
        /// that represents this fixed page within the package.

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