SubtitleEdit/subtitleedit · error · OcrException

Error calling Cloud Vision API: {httpException.Message}

Error message

Error calling Cloud Vision API: {httpException.Message}

What it means

Thrown by GoogleVisionOcr.Ocr when PostAsync raises HttpRequestException — i.e. the call never reached a HTTP response. This covers DNS failure, connection refused, TLS errors, socket exhaustion, and timeouts at the transport layer. The original HttpRequestException is preserved as InnerException.

Source

Thrown at src/ui/Features/Ocr/Engines/GoogleVisionOcr.cs:207

            {
                throw new OcrException("API key invalid (or perhaps billing/API is not enabled)?");
            }

            if ((int)result.StatusCode == 403)
            {
                throw new OcrException("\"Perhaps billing is not enabled (or API not enabled or API key is invalid)?\"");
            }

            if (!result.IsSuccessStatusCode)
            {
                throw new OcrException($"An error occurred calling Cloud Vision API - status code: {result.StatusCode}");
            }

            content = await result.Content.ReadAsStringAsync(cancellationToken);
        }
        catch (HttpRequestException httpException)
        {
            throw new OcrException("Error calling Cloud Vision API: " + httpException.Message, httpException);
        }

        return string.Join(Environment.NewLine, JsonToStringList(language, content));
    }

    public static List<string> JsonToStringList(string language, string content)
    {
        if (Configuration.Settings.Tools.OcrGoogleCloudVisionSeHandlesTextMerge)
        {
            var annotations = GetAnnotations(content).ToList();
            if (annotations.Count > 0)
            {
                var lines = new List<List<Annotation>>();
                Annotation? last = null;
                var lineThreshold = Math.Max(9, annotations.Average(p => p.Height) / 4.0);
                var lineIndex = 0;

                // Split to lines

View on GitHub (pinned to 17a9f07487)

Solutions

1. Confirm network connectivity and that vision.googleapis.com resolves.
2. Configure the HttpClient with the required proxy (HttpClientHandler.Proxy / WebProxy).
3. Update the system certificate store / .NET root certificates for TLS.
4. Retry transient network blips; if persistent, fall back to a local OCR engine (tesseract/nocr).

Example fix

// configure proxy on the HttpClient handed to GoogleVisionOcr
var handler = new HttpClientHandler { UseProxy = true, Proxy = new WebProxy("http://proxy:8080") };
var http = new HttpClient(handler) { BaseAddress = new Uri("https://vision.googleapis.com/v1/images:annotate") };

// Pre-flight connectivity check
try { await _httpClient.GetAsync("/", ct); } catch (HttpRequestException ex) { throw new OcrException("Cannot reach Vision API: " + ex.Message, ex); }

null

try { return await ocr.Ocr(bmp, key, lang, ct); }
catch (OcrException ex) when (ex.InnerException is HttpRequestException) {
    // network/proxy/TLS — retry once or fall back to a local OCR engine
    return await FallbackLocalOcr(bmp); }

When it happens

Trigger: _httpClient.PostAsync throws HttpRequestException (no response obtained): offline, no network, DNS for the Vision host fails, proxy blocks the call, or TLS handshake fails.

Common situations: Running OCR offline or behind a corporate proxy that blocks vision.googleapis.com; DNS misconfiguration; expired/missing root certificates; HttpClient disposed mid-call.

Related errors

• API key invalid (or perhaps billing/API is not enabled)?
• "Perhaps billing is not enabled (or API not enabled or API k
• An error occurred calling Cloud Vision API - status code: {r
• Location header not found
• llama.cpp returned {(int)resp.StatusCode}: {json}

AI-assisted analysis of SubtitleEdit/subtitleedit@17a9f07487 (2026-08-13). Data as JSON: /api/errors/20de4fd195e38c40. Report an issue: GitHub.