beeradmoore/dlss-swapper · error · Exception

dlss_presets.json is empty or invalid.

Error message

dlss_presets.json is empty or invalid.

What it means

NVAPIHelper throws this when it loads dlss_presets.json to build the DLSS preset option list, but the file's parsed content is empty or fails validation, so no preset options can be constructed. It indicates the embedded/shipped dlss_presets.json resource is missing its expected preset data or has an invalid structure.

Solutions

1. Verify dlss_presets.json is present and contains a non-empty, valid presets array (validate with a JSON linter/schema check).
2. Restore the original dlss_presets.json from a clean install or the repository.
3. Reinstall/repair the application so the resource is correctly embedded/deployed.
4. If customizing the file, match the exact schema NVAPIHelper expects before loading.

Example fix

// before (broken file)
{}
// after (valid presets file)
{ "presets": [ { "id": 1, "name": "Quality" } ] }

var json = File.ReadAllText(presetPath);
var data = JsonSerializer.Deserialize<DlssPresets>(json);
if (data == null || data.Presets == null || data.Presets.Count == 0)
    throw new InvalidDataException($"{presetPath} is empty or has no presets.");

try { InitDlssPresets(); }
catch (Exception ex) when (ex.Message.Contains("dlss_presets.json"))
{ Logger.Error(ex); ShowFallbackPresetList(); }

When it happens

Trigger: Calling the NVAPIHelper initialization that builds DlssPresetOptions when dlss_presets.json exists but deserializes to null/empty or lacks the expected preset entries (the else branch after a successful file read).

Common situations: App installed from a broken/partial build where the resource wasn't embedded; the JSON was hand-edited or truncated; a version change renamed or restructured the JSON schema; deployment stripped resource files.

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

• Could not deserialize manifest.json.
• Could not deserialize GOGCatalogResponse for url
• Could not deserialize GOGEmbedFilteredResponse for url
• Could not load GitHub release data.
• LibraryPage_ZipDidNotContainAnyDlls

AI-assisted analysis of beeradmoore/dlss-swapper@ab9b1e2d4b (2026-09-15). Data as JSON: /api/errors/17ae5dd49d8e9a77. Report an issue: GitHub.

Appendix: source

Thrown at src/Helpers/NVAPIHelper.cs:124

    {
        // Load DLSS presets
        try
        {
            var dlssPresetsJsonPath = @"Assets\dlss_presets.json";
            if (File.Exists(dlssPresetsJsonPath) == true)
            {
                var dlssPresetOptions = JsonSerializer.Deserialize(File.ReadAllText(dlssPresetsJsonPath), SourceGenerationContext.Default.ListPresetOption)?.Where(x => x.Used == true)?.ToList();
                if (dlssPresetOptions is not null && dlssPresetOptions.Count > 0)
                {
                    for (var i = 0; i < dlssPresetOptions.Count; ++i)
                    {
                        dlssPresetOptions[i].UpdateNameFromTranslation();
                    }
                    DlssPresetOptions = dlssPresetOptions.AsReadOnly();
                }
                else
                {
                    throw new Exception("dlss_presets.json is empty or invalid.");
                }
            }
            else
            {
                throw new Exception("dlss_presets.json not found.");
            }
        }
        catch (Exception err)
        {
            Logger.Error(err, "Could not load dlss_presets.json, using default presets.");
            DlssPresetOptions = [
                new PresetOption(ResourceHelper.GetString("DLSS_Preset_Default"), 0x00000000),
                new PresetOption(ResourceHelper.GetFormattedResourceTemplate("DLSS_Preset_Letter", "A"), 0x00000001),
                new PresetOption(ResourceHelper.GetFormattedResourceTemplate("DLSS_Preset_Letter", "B"), 0x00000002),
                new PresetOption(ResourceHelper.GetFormattedResourceTemplate("DLSS_Preset_Letter", "C"), 0x00000003),
                new PresetOption(ResourceHelper.GetFormattedResourceTemplate("DLSS_Preset_Letter", "D"), 0x00000004),
                new PresetOption(ResourceHelper.GetFormattedResourceTemplate("DLSS_Preset_Letter", "E"), 0x00000005),
                new PresetOption(ResourceHelper.GetFormattedResourceTemplate("DLSS_Preset_Letter", "F"), 0x00000006),

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