SixLabors/ImageSharp · error · InvalidIccProfileException

Profile description can only have multi-localized Unicode…

Error message

Profile description can only have multi-localized Unicode or text description entries

What it means

A profile description tag (desc) must be either a multiLocalizedUnicodeType or (legacy) textDescriptionType. When the reader sees any other type signature under a profileDescriptionTag it throws, since the description cannot be interpreted as localizable text.

Solutions

Re-export the profile with a standards-compliant description (multiLocalizedUnicode).
Pre-validate the profile with an ICC conformance checker and fix the desc tag.
If you only need the raw bytes, parse the tag yourself with ReadTagDataEntry instead of ReadProfileDescription.
Catch InvalidIccProfileException and substitute a placeholder description.

Defensive patterns

Strategy: try-catch

Try / catch

try { profile = IccReader.Read(stream); }
catch (InvalidIccProfileException ex) when (ex.Message.Contains("description"))
{
    // use file name or fallback description
    return new IccProfileDescription { DeviceManufacturer = "unknown" };
}

Prevention

Regenerate non-conformant profiles with modern tooling
Pre-validate desc tag type with ICC verification tools
Do not assume all vendor profiles are spec-compliant
Store expected descriptions out-of-band for known profiles

When it happens

Trigger: Parsing an ICC profile whose desc tag carries a type signature other than multiLocalizedUnicode or textDescription (e.g. a plain textType or corrupt bytes); reading profiles via ReadProfileDescription from a profile-sequence-desc context.

Common situations: Non-conformant profiles written by buggy tools that store textType in the desc tag; corrupted profile files; very old or exotic profiles with custom description encodings.

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 SixLabors/ImageSharp@59ce6af6fc (2026-09-13). Data as JSON: /api/errors/f8dd3ef5d00fc815. Report an issue: GitHub.

Appendix: source

Thrown at src/ImageSharp/Metadata/Profiles/ICC/DataReader/IccDataReader.NonPrimitives.cs:150

            manufacturer,
            model,
            attributes,
            technologyInfo,
            manufacturerInfo.Texts,
            modelInfo.Texts);

        IccMultiLocalizedUnicodeTagDataEntry ReadText()
        {
            IccTypeSignature type = this.ReadTagDataEntryHeader();
            switch (type)
            {
                case IccTypeSignature.MultiLocalizedUnicode:
                    return this.ReadMultiLocalizedUnicodeTagDataEntry();
                case IccTypeSignature.TextDescription:
                    return (IccMultiLocalizedUnicodeTagDataEntry)this.ReadTextDescriptionTagDataEntry();

                default:
                    throw new InvalidIccProfileException("Profile description can only have multi-localized Unicode or text description entries");
            }
        }
    }

    /// <summary>
    /// Reads a colorant table entry
    /// </summary>
    /// <returns>the profile description</returns>
    public IccColorantTableEntry ReadColorantTableEntry()
    {
        return new IccColorantTableEntry(
            name: this.ReadAsciiString(32),
            pcs1: this.ReadUInt16(),
            pcs2: this.ReadUInt16(),
            pcs3: this.ReadUInt16());
    }

    /// <summary>

View on GitHub (pinned to 59ce6af6fc)