dotnet/wpf · error · XpsSerializationException

SR.ReachSerialization_FixedDocumentInPage

Error message

SR.ReachSerialization_FixedDocumentInPage

What it means

RegisterDocumentStart also rejects starting a document while a page is still open (_pageStartState). If a FixedPage has been started but not ended, starting a FixedDocument would illegally nest a document inside a page, so XpsSerializationException(SR.ReachSerialization_FixedDocumentInPage) is thrown.

Solutions

Ensure RegisterPageEnd (and page commit) is always called before RegisterDocumentStart, including on error paths (try/finally).
Restructure pagination so documents and pages nest correctly: DocumentSequence > Document > Page.
Add assertions/logging around the register calls to catch ordering bugs early.
Use DocumentPaginator + XpsDocumentWriter to let WPF manage document/page sequencing.

Example fix

// before
manager.RegisterPageStart();
manager.RegisterDocumentStart(); // document inside open page
// after
manager.RegisterPageStart();
manager.RegisterPageEnd();
manager.RegisterDocumentEnd();
manager.RegisterDocumentStart();

Defensive patterns

Strategy: validation

Validate before calling

if (pageOpen)
    throw new InvalidOperationException("Cannot start a FixedDocument while a FixedPage is open; call RegisterPageEnd first.");

Try / catch

try
{
    manager.RegisterDocumentStart();
}
catch (System.Windows.Xps.XpsSerializationException ex) when (ex.Message.Contains("page"))
{
    // close the dangling page/document chain before retrying
    manager.RegisterPageEnd();
    manager.RegisterDocumentEnd();
    manager.RegisterDocumentStart();
}

Prevention

Wrap page serialization in try/finally so RegisterPageEnd always runs, even on exceptions.
Nest calls in the correct order: sequence start > document start > page start/end > document end > sequence end.
Log each register call in debug builds to catch ordering violations early.

When it happens

Trigger: Calling RegisterDocumentStart after RegisterPageStart without RegisterPageEnd — e.g. a paginator that begins a new document mid-page, or missing/failed page-end cleanup on an exception path.

Common situations: Error-handling gaps where RegisterPageEnd is skipped after a serialization failure; per-page document rotation logic in custom XPS writers; async serialization callbacks firing out of order.

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/037983191b5d29fb. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/ReachFramework/Serialization/manager/XpsSerializationManager.cs:844

        AddRelationshipToCurrentPage(
            Uri targetUri,
            string relationshipName
            )
        {
            _packagingPolicy?.RelateResourceToCurrentPage(targetUri, relationshipName);
        }

        internal
        void
        RegisterDocumentStart()
        {
            if( _documentStartState )
            {
                throw new XpsSerializationException(SR.ReachSerialization_FixedDocumentInDocument);
            }
            if( _pageStartState)
            {
                throw new XpsSerializationException(SR.ReachSerialization_FixedDocumentInPage);
            }
            //
            // Entering Document  Started state
            //
            _documentStartState = true;
            //
            // Increment the number of documents serialized
            //
            _documentNumber += 1;
            //
            // Clearing the number of pages for this document
            //
            _pageNumber = 0;
        }


        internal
        void

View on GitHub (pinned to 81131a70a4)