dotnet/wpf · error · COMException

E_FAIL

E_FAIL

Error message

File to filter is not loaded.

What it means

XpsFilter.Init implements IFilter.Init and requires that a file first be loaded via IPersistFile.Load, which sets _filter. If no file was loaded, _filter is null and Init throws COMException with E_FAIL.

Solutions

1. Call IPersistFile.Load(path) on the XpsFilter instance before calling IFilter.Init
2. Check that the file passed to Load is a valid XPS or encrypted OPC package
3. Handle the COMException (E_FAIL) and re-load the filter before retrying

Example fix

// before
var filter = new XpsFilter();
filter.Init(IFILTER_INIT.IFILTER_INIT_CANON_PARAGRAPHS, 0, null);
// after
var filter = new XpsFilter();
((IPersistFile)filter).Load(path, STGM.READ);
filter.Init(IFILTER_INIT.IFILTER_INIT_CANON_PARAGRAPHS, 0, null);

try { ((IPersistFile)filter).Load(path, STGM.READ); }
catch (COMException) { /* abort indexing for this file */ }
try { filter.Init(flags, 0, null); }
catch (COMException ex) when (ex.ErrorCode == unchecked((int)0x80004005)) { /* re-load or skip */ }

When it happens

Trigger: Calling IFilter.Init on an XpsFilter instance without previously calling IPersistFile.Load with a valid package file path, or after Load failed without checking.

Common situations: Indexing/preview infrastructure instantiating XpsFilter directly and calling IFilter methods out of order, or Load failing because the path is not a valid XPS/OPC package.

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

• FILTER_E_ACCESS
• E_INVALIDARG
• E_NOTIMPL
• Buffer address passed to GetText cannot be NULL.
• PrintingCanceledException

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/8939843eced0a50e. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationFramework/MS/Internal/IO/Packaging/XpsFilter.cs:54

        /// <summary>
        /// Initialzes the session for this filter.
        /// </summary>
        /// <param name="grfFlags">usage flags</param>
        /// <param name="cAttributes">number of elements in aAttributes array</param>
        /// <param name="aAttributes">array of FULLPROPSPEC structs to restrict responses</param>
        /// <returns>
        /// IFILTER_FLAGS_NONE to indicate that the caller should not use the IPropertySetStorage
        /// and IPropertyStorage interfaces to locate additional properties.
        /// </returns>
        IFILTER_FLAGS IFilter.Init(
            [In] IFILTER_INIT grfFlags,
            [In] uint cAttributes,
            [In, MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 1)] FULLPROPSPEC[] aAttributes)
        {
            if (_filter == null)
            {
                throw new COMException(SR.FileToFilterNotLoaded,
                    (int)NativeMethods.E_FAIL);
            }

            if (cAttributes > 0 && aAttributes == null)
            {
                // Attributes count and array do not match.
                throw new COMException(SR.FilterInitInvalidAttributes,
                    (int)NativeMethods.E_INVALIDARG);
            }

            return _filter.Init(grfFlags, cAttributes, aAttributes);
        }

        /// <summary>
        /// Returns description of the next chunk.
        /// </summary>
        /// <returns>Chunk descriptor</returns>
        STAT_CHUNK IFilter.GetChunk()

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