SubtitleEdit/subtitleedit · error · InvalidOperationException

Output folder is not set

Error message

Output folder is not set

What it means

Thrown by MakeOutputFileName when it cannot resolve a non-empty output directory. The folder is derived either from the source file's directory (when SaveInSourceFolder is true or OutputFolder is empty) or from _config.OutputFolder. Path.GetDirectoryName returns null for root-level paths like "C:\" or empty strings, and if OutputFolder is also empty the method has nowhere to write.

Source

Thrown at src/ui/Features/Tools/BatchConvert/BatchConverter.cs:2915

        var kept = subtitle.Paragraphs
            .Where((_, idx) => !removed.Contains(idx))
            .ToList();
        subtitle.Paragraphs.Clear();
        subtitle.Paragraphs.AddRange(kept);
        subtitle.Renumber();

        return subtitle;
    }

    private string MakeOutputFileName(BatchConvertItem item, string extension)
    {
        var outputFolder = _config.SaveInSourceFolder || string.IsNullOrEmpty(_config.OutputFolder)
            ? Path.GetDirectoryName(item.FileName)
            : _config.OutputFolder;
        if (string.IsNullOrEmpty(outputFolder))
        {
            throw new InvalidOperationException("Output folder is not set");
        }

        var fileName = Path.GetFileNameWithoutExtension(item.FileName);
        if (!string.IsNullOrEmpty(item.OutputFileName))
        {
            fileName = Path.GetFileNameWithoutExtension(item.OutputFileName);
        }

        var targetExtension = extension;

        if (!string.IsNullOrEmpty(item.LanguageCode))
        {
            if (Se.Settings.Tools.BatchConvert.LanguagePostFix == Se.Language.General.TwoLetterLanguageCode)
            {
                var code = item.LanguageCode;
                if (code.Length == 3)
                {
                    code = Iso639Dash2LanguageCode.GetTwoLetterCodeFromThreeLetterCode(code);

View on GitHub (pinned to 17a9f07487)

Solutions

1. Ensure _config.OutputFolder is set to a valid absolute path before batch conversion if not saving to source folder.
2. Validate that each BatchConvertItem.FileName contains a directory component (not a bare filename or root path) before starting conversion.
3. If SaveInSourceFolder is false, verify the OutputFolder setting in the BatchConvert configuration dialog is populated.
4. Add a pre-flight check on all items before the batch loop to surface the problematic file name early.

Example fix

// before
var outputFolder = _config.SaveInSourceFolder || string.IsNullOrEmpty(_config.OutputFolder)
    ? Path.GetDirectoryName(item.FileName)
    : _config.OutputFolder;
if (string.IsNullOrEmpty(outputFolder))
{
    throw new InvalidOperationException("Output folder is not set");
}

// after — fall back to a sensible default and give a precise message
var outputFolder = _config.SaveInSourceFolder || string.IsNullOrEmpty(_config.OutputFolder)
    ? Path.GetDirectoryName(item.FileName)
    : _config.OutputFolder;
if (string.IsNullOrEmpty(outputFolder))
{
    throw new InvalidOperationException(
        $"Output folder is not set for '{item.FileName}'. " +
        $"SaveInSourceFolder={_config.SaveInSourceFolder}, OutputFolder='{_config.OutputFolder}'. " +
        "Set an output folder in Batch Convert settings or ensure the input file has a directory path.");
}

// Pre-flight check before batch conversion
foreach (var item in items)
{
    var dir = _config.SaveInSourceFolder || string.IsNullOrEmpty(_config.OutputFolder)
        ? Path.GetDirectoryName(item.FileName)
        : _config.OutputFolder;
    if (string.IsNullOrEmpty(dir))
        throw new InvalidOperationException($"Cannot resolve output folder for '{item.FileName}'. Set OutputFolder or ensure file has a directory path.");
}

When it happens

Trigger: SaveInSourceFolder is true (or OutputFolder is empty) AND Path.GetDirectoryName(item.FileName) returns null — this happens when item.FileName is a root path like "C:" or "\". Alternatively, SaveInSourceFolder is false and _config.OutputFolder is null or whitespace.

Common situations: A file dragged from a root drive letter without a path separator; a UNC path that GetDirectoryName mishandles; the batch convert OutputFolder setting was cleared in configuration; a programmatic batch run where item.FileName was set to a bare filename without a directory component.

Related errors

• Color '{colorName}' not found in SKColors.
• Dvd language {code} not found!
• Problem accessing RIFF file {FileName}
• Problem reading data in file {FileName}
• Model file not found.

AI-assisted analysis of SubtitleEdit/subtitleedit@17a9f07487 (2026-08-13). Data as JSON: /api/errors/a5e069bfe1685b6a. Report an issue: GitHub.