What causes "XML file not found" in dotnet/wpf?

Verify the path passed for the XML file exists: run File.Exists / ls on the exact path.

dotnet/wpf · error · FileNotFoundException

XML file not found

Error message

XML file not found

What it means

ResourceGenerator.ProcessArgs validates its command-line inputs after parsing and throws FileNotFoundException when the XML data file supplied via parsedArgs.xmlFile does not exist on disk. This is a fail-fast check so the generator stops before attempting to load a missing resource model.

Solutions

Verify the path passed for the XML file exists: run File.Exists / ls on the exact path.
Use an absolute path in the build script to avoid working-directory surprises.
Fix the argument in the invoking script/target, or check out/restore the missing XML file.
Check case sensitivity of the file name on Linux-style filesystems.

Example fix

// before
csp ResourceGenerator model.xml
// (model.xml not in current dir)
// after
csp ResourceGenerator $(MSBuildProjectDirectory)\Resources\model.xml

Defensive patterns

Strategy: validation

Validate before calling

if (!File.Exists(xmlPath))
    throw new FileNotFoundException($"XML data file missing: {Path.GetFullPath(xmlPath)}");

Try / catch

try { generator.ProcessArgs(args); }
catch (FileNotFoundException ex) when (ex.FileName == xmlPath) { Console.Error.WriteLine($"XML file not found: {ex.FileName}"); return 2; }

Prevention

Use absolute paths in build scripts and CI.
Check File.Exists on all inputs before invoking the generator.
Ensure the XML data file is committed/generated before the tool runs.

When it happens

Trigger: Running the ResourceGenerator tool with a path to the XML file that does not exist: misspelled file name, wrong working directory, relative path resolved from an unexpected location, or the file was deleted/moved before the run.

Common situations: Build scripts or MSBuild targets invoking the tool from a different working directory than expected; CI checkouts missing generated or checked-in XML data files; typos in the XML path argument.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/3124ccea6a8724fe. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/WpfGfx/codegen/mcg/main/ResourceGenerator.cs:186

            //
            // Handle "-h" option.
            //

            if (parsedArgs.help)
            {
                Usage();
                resourceModel = null;
                return;
            }


            //
            // Check that files exist
            //

            if (!File.Exists(parsedArgs.xmlFile))
            {
                throw new FileNotFoundException("XML file not found", parsedArgs.xmlFile);
            }

            if (!File.Exists(parsedArgs.xsdFile))
            {
                throw new FileNotFoundException("Schema not found", parsedArgs.xsdFile);
            }

            //
            // Load the XML file and create the resource model from it
            //

            XmlDocument document = LoadDocument(parsedArgs.xmlFile, parsedArgs.xsdFile);
            resourceModel = new ResourceModel(document, parsedArgs.outputDirectory);
        }

        public static void ReportArgumentError(string message)
        {
            Usage();

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