DefaultPageSettings.PaperSize can terminate the process with 0xc0000005 for an offline printer queue #15200

Disclosure: This issue report was prepared by OpenAI Codex, an AI coding agent, from diagnostic information and test results supplied by the application developer. The report should be reviewed by a human before submission. Customer-identifying information has intentionally been omitted.

.NET version

• Target framework: net10.0-windows
• Process architecture: x64
• .NET runtime: 10.0.12
• CoreCLR: 10.0.1226.42308
• Application type: WPF application using System.Drawing.Printing.PrinterSettings

Description

Reading PrinterSettings.DefaultPageSettings.PaperSize for one or more offline printer queues can terminate the entire process with native exception code 0xc0000005.

The failure cannot be caught by normal managed try/catch; the process terminates before error logging in the catch block can run.

The problem reproduces on a customer Windows system but not on the developer workstation or server. The application starts normally when printer detail reads are disabled. Isolating the queried properties showed:

• Printer enumeration succeeds.
• Reading PrintQueue.IsOffline succeeds.
• Reading PrinterSettings.PrinterResolutions succeeds.
• Reading PrinterSettings.DefaultPageSettings.PaperSize causes the native crash.
• Skipping printer detail reads when PrintQueue.IsOffline == true prevents the crash. The resulting build has been deployed to the customer and operates successfully.

This may ultimately be caused by a printer driver returning malformed DEVMODE data. Nevertheless, a public managed property getter terminating the process without a catchable managed exception is unexpected.

Minimal code path

using System.Drawing.Printing;
using System.Printing;

using var server = new LocalPrintServer();
var queues = server.GetPrintQueues(
    [EnumeratedPrintQueueTypes.Local, EnumeratedPrintQueueTypes.Connections]);

foreach (var queue in queues)
{
    Console.WriteLine($"{queue.FullName}: IsOffline={queue.IsOffline}");

    var settings = new PrinterSettings
    {
        PrinterName = queue.FullName
    };

    // PrinterResolutions succeeds on the affected system.
    var resolutions = settings.PrinterResolutions;

    // For an offline queue this can terminate the process with 0xc0000005.
    var paperSize = settings.DefaultPageSettings.PaperSize;

    Console.WriteLine($"{paperSize.Width} x {paperSize.Height}");
}

The issue currently depends on the affected customer printer/driver configuration; a hardware-independent reproduction has not yet been produced.

Expected behavior

The getter should return the paper size or throw a managed exception describing an invalid/unavailable printer or invalid driver data. It should not terminate the process.

Actual behavior

Windows Application Error / .NET Runtime event:

Application: FiftyWorker.exe
CoreCLR Version: 10.0.1226.42308
.NET Version: 10.0.12
Description: The process was terminated due to an unhandled exception.
Stack:
   at Windows.Win32.PInvoke.DocumentProperties(...)
   at Windows.Win32.PInvoke.DocumentProperties(...)
   at System.Drawing.Printing.PrinterSettings.GetHdevmodeInternal(Char*)
   at System.Drawing.Printing.PrinterSettings.GetHdevmode()
   at System.Drawing.Printing.PageSettings.get_PrinterResolution()
   at FiftyWorker.Local.GetPrinterList()
   at FiftyWorker.MainWindow..ctor()
   at FiftyWorker.Program.Main(System.String[])

A later property-isolation test identified DefaultPageSettings.PaperSize as the crashing read. Both PageSettings.PaperSize and PageSettings.PrinterResolution use the same GetHdevmode() path.

The corresponding Application Error entry was:

Faulting module: coreclr.dll, version 10.0.1226.42308
Exception code: 0xc0000005
Fault offset: 0x00000000003596cf

Workaround

Read PrintQueue.IsOffline before creating/querying PrinterSettings, and skip DefaultPageSettings for offline queues:

if (queue.IsOffline)
{
    continue;
}

var settings = new PrinterSettings { PrinterName = queue.FullName };
var paperSize = settings.DefaultPageSettings.PaperSize;

Similar issue search

No issue matching the offline-printer 0xc0000005 failure was found in dotnet/winforms using these searches:

• DocumentProperties GetHdevmode
• DefaultPageSettings.PaperSize AccessViolation
• GetHdevmode crash
• printer offline access violation

The closest result is #8812, which contains the same PaperSize -> GetHdevmode -> DocumentProperties stack but concerns missing winspool.drv on Windows Nano Server and is not a duplicate of this failure.

Additional information still needed

• Exact Windows edition, version and OS build from the affected system.
• Affected printer queue type: local, shared/network connection, redirected, or other.
• Printer model, driver name, driver provider, driver version/date, INF name and port type. Queue/server/customer names may be anonymized.
• Whether the queue was already offline when the process started.
• Whether the failure remains after restarting the Print Spooler or recreating that exact queue.
• If safely obtainable outside production: a crash dump captured for the original failing build and analyzed with native symbols.
• Result with the latest supported .NET 10 servicing runtime, if newer than 10.0.12 is available when the report is submitted.
• Whether a minimal standalone x64 console/WPF application reproduces on the affected system.

Safe collection commands for the affected machine

These commands only read system/spooler metadata. They do not query DefaultPageSettings.PaperSize and therefore do not intentionally execute the crashing code path.

Get-ComputerInfo |
    Select-Object WindowsProductName, WindowsVersion, OsBuildNumber, OsArchitecture

dotnet --info
dotnet --list-runtimes

Get-CimInstance Win32_Printer |
    Select-Object Name, DriverName, PortName, Network, Shared, WorkOffline,
        PrinterStatus, DetectedErrorState

Get-CimInstance Win32_PrinterDriver |
    Select-Object Name, Version, InfName, DriverPath, SupportedPlatform

Review and anonymize printer names, server names, port names, user names and local paths before posting the output publicly.