dotnet/wpf · error · FileFormatException

SR.CFRCorruptMultiStream

Error message

SR.CFRCorruptMultiStream

What it means

CompoundFileReference.Load() parses a serialized reference and found a second Stream component in a single reference entry, which the format forbids. A valid compound-file reference may name at most one storage and one stream; encountering a second stream means the serialized data is malformed or truncated/corrupted. The library fails fast with FileFormatException rather than misinterpreting the bytes.

Solutions

1. Verify the file is not corrupted: re-obtain it from the source and compare checksums or re-download in binary mode.
2. Validate that the file was written by a conformant compound-file writer; re-generate it with the official packaging APIs (System.IO.Packaging / ZipPackage or valid OCG/CPF writer).
3. Wrap the Load call in try/catch for FileFormatException and treat it as invalid input, showing a user-facing 'file is corrupted' message.
4. If constructing references programmatically, do not serialize multiple Stream components into one reference.

Example fix

// before
var reference = CompoundFileReference.Load(binaryReader); // throws FileFormatException on corrupt data
// after
CompoundFileReference reference;
try { reference = CompoundFileReference.Load(binaryReader); }
catch (FileFormatException) { throw new InvalidDataException("The compound file reference data is corrupt."); }

if (reader.BaseStream.Length - reader.BaseStream.Position < 8) throw new InvalidDataException("Not enough bytes for a compound-file reference.");

static bool IsValidCompoundFileData(Stream s) => s != null && s.CanRead && s.Length > 0;

try { var r = CompoundFileReference.Load(reader); }
catch (FileFormatException ex) { log.Warn(ex, "Corrupt compound-file reference"); throw new InvalidDataException("File is corrupt.", ex); }

When it happens

Trigger: Calling CompoundFileReference.Load (or loading a compound-file container that stores references) over a byte stream whose reference record lists Stream component type more than once for one entry.

Common situations: Hand-edited or corrupted compound files, files produced by buggy third-party writers, files truncated by incomplete downloads or transfer in text mode, or fuzzed input to code that opens XPS/compound-file packages.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• SR.UnknownReferenceComponentType
• String format is not valid.
• ' ' cannot contain the path delimiter: ' '.
• ' ' cannot start with the reserved character range…
• ' ' ID is not a valid XSD ID.

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/6c564a2e57c35a03. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/WindowsBase/MS/Internal/IO/Packaging/CompoundFile/CompoundFileReference.cs:203

                switch (refType)
                {
                    case RefComponentType.Storage:
                    {
                        if (streamName != null)
                            throw new FileFormatException(
                                SR.CFRCorruptStgFollowStm);

                        if (storageList == null)
                            storageList = new StringCollection();

                        String str = ContainerUtilities.ReadByteLengthPrefixedDWordPaddedUnicodeString(reader, out byteLength);
                        bytesRead += byteLength;
                        storageList.Add(str);
} break;
                    case RefComponentType.Stream:
                    {
                        if (streamName != null)
                            throw new FileFormatException(
                                SR.CFRCorruptMultiStream);

                        streamName = ContainerUtilities.ReadByteLengthPrefixedDWordPaddedUnicodeString(reader, out byteLength);
                        bytesRead += byteLength;
                    } break;

                    // we don't handle these types yet
                    default:
                        throw new FileFormatException(
                            SR.UnknownReferenceComponentType);
                }

                --entryCount;
            }

            CompoundFileReference newRef = null;

            // stream or storage?

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