---
title: "Troubleshoot uploads, captions, previews and exports"
description: "Fix the most common workflow problems and collect the right safe details for support."
url: https://help.clipsubtitles.com/en/articles/11-troubleshoot-uploads-captions-previews-and-exports
collection: "Troubleshooting"
updated: 2026-10-15
language: en
---

# Troubleshoot uploads, captions, previews and exports

Fix the most common workflow problems and collect the right safe details for support.

### Upload does not start

-   Confirm the file is no larger than 500 MB and no longer than 10 minutes.
    
-   Use a supported media type.
    
-   If importing a URL, confirm it points directly to public media rather than a webpage or sign-in screen.
    
-   Keep the tab open until a browser upload reports completion.
    
-   If the upload link expired, create a new target and try again.
    

### Caption generation is waiting or failed

Generation runs as a background task. Refresh the project and check the task state. If it fails, keep the visible `errorRef`, approximate time and project ID. Do not include transcript text unless the words themselves demonstrate the problem.

### One word is wrong

Edit that word directly. Use regeneration only when the wider transcript or segmentation is wrong. If names or specialist terms are consistently misheard, provide a small vocabulary list before generation when using the API or MCP tool.

### The preview looks different from the editor

Confirm you previewed the latest project version. Any text, timing, style or placement change creates a new version. Generate a new preview after saving the change.

### The export quote changed or expired

Quotes are tied to the project version, settings and current price version and normally expire after 15 minutes. Request a fresh quote. Do not try to approve an old quote after editing the project.

### A render is stuck

Check the task state rather than starting duplicate renders. If you used the API or MCP, poll with bounded backoff. You can request cancellation while the task is queued or running. Finished tasks cannot be cancelled.

### A download link expired

Return to the project or **Exports** and request the download again while the export is still retained. Do not reuse a saved signed URL.

### An agent cannot connect

Confirm the client supports a remote Streamable HTTP MCP server with OAuth. Use `https://api.clipsubtitles.com/api/mcp`, complete browser sign-in and approve the expected scopes. Never paste a token into chat. Revoke the connection in Settings before reconnecting if the wrong client or account was authorized.

### Contact support

Send `support@clipsubtitles.com` the expected and actual result, exact non-secret error text or `errorRef`, approximate time and timezone, browser/platform, whether it reproduces, and the affected project/task/export ID when safe. A redacted screenshot is useful. Never send passwords, authentication codes, API keys, access tokens, card details or private signed URLs.