What causes "SeekOrigin value is not valid." in dotnet/wpf?

Only pass SeekOrigin.Begin, SeekOrigin.Current, or SeekOrigin.End — never raw ints cast to SeekOrigin.

dotnet/wpf · error · ArgumentOutOfRangeException

SeekOrigin value is not valid.

Error message

SeekOrigin value is not valid.

What it means

RightsManagementEncryptedStream.Seek supports only SeekOrigin.Begin, SeekOrigin.Current, and SeekOrigin.End. A value outside the defined SeekOrigin enum hits the switch's default case and throws ArgumentOutOfRangeException with the 'SeekOrigin value is not valid' message.

Solutions

Only pass SeekOrigin.Begin, SeekOrigin.Current, or SeekOrigin.End — never raw ints cast to SeekOrigin.
Map native seek constants to the correct SeekOrigin member before calling.
Catch ArgumentOutOfRangeException to detect a bad origin value and log it.

Example fix

// before
stream.Seek(offset, (SeekOrigin)seekConst); // interop constant
// after
var origin = seekConst == 0 ? SeekOrigin.Begin : seekConst == 1 ? SeekOrigin.Current : SeekOrigin.End;
stream.Seek(offset, origin);

Defensive patterns

Strategy: type-guard

Validate before calling

bool IsValidOrigin(SeekOrigin o) => o is SeekOrigin.Begin or SeekOrigin.Current or SeekOrigin.End;

Type guard

static bool TryGetSeekOrigin(int raw, out SeekOrigin origin) {
    switch (raw) {
        case 0: origin = SeekOrigin.Begin; return true;
        case 1: origin = SeekOrigin.Current; return true;
        case 2: origin = SeekOrigin.End; return true;
        default: origin = default; return false;
    }
}

Try / catch

try { stream.Seek(offset, origin); }
catch (ArgumentOutOfRangeException ex) { /* ex.ParamName == "origin"; map native constant and retry */ }

Prevention

Never cast raw ints to SeekOrigin; map native seek constants explicitly
Use Enum.IsDefined(typeof(SeekOrigin), value) before casting
Centralize seek-origin translation in one helper for interop code

When it happens

Trigger: Calling Seek with an origin value not in the SeekOrigin enum, e.g. stream.Seek(offset, (SeekOrigin)3) — commonly via a cast from an int/interop value.

Common situations: Interop code passing native SEEK_SET/SEEK_CUR/SEEK_END values (0/1/2 semantics may differ) or integer flags cast to SeekOrigin without mapping.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/9bd01b4d06b444c0. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/WindowsBase/MS/Internal/IO/Packaging/CompoundFile/RightsManagementEncryptedStream.cs:142

                {
                    case SeekOrigin.Begin:
                        {
                            temp = offset;
                            break;
                        }
                    case SeekOrigin.Current:
                        {
                            temp = _streamPosition + offset;
                            break;
                        }
                    case SeekOrigin.End:
                        {
                            temp = Length + offset;
                            break;
                        }
                    default:
                        {
                            throw new ArgumentOutOfRangeException(nameof(origin), SR.SeekOriginInvalid);
                        }
                }
            }
            
            if (temp < 0)
            {
                throw new ArgumentOutOfRangeException(nameof(offset), SR.SeekNegative);
            }

            _streamPosition = temp;
            return _streamPosition;
        }        

        /// <summary>
        /// See .NET Framework SDK under System.IO.Stream
        /// </summary>
        public override void SetLength(long newLength)
        {

View on GitHub (pinned to 81131a70a4)