Introduction
Finding that the Auto-Translate function in Subtitle Edit is either grayed out, failing to connect, or starting the process but returning empty lines can completely derail your workflow. This failure means the software cannot establish or maintain a clean, valid connection to the external translation API (such as Google Translate or DeepL).
The root cause is almost always a configuration problem: either an invalid API key, an outdated software version with a broken endpoint, or a network firewall blocking the required internet access. By systematically troubleshooting these connection and setup issues, you can restore the translation feature’s full functionality.
What Causes the Auto-Translate Feature to Fail or Be Grayed Out?
The translation feature requires three specific components to function: a valid software version, a correct API key, and an open network connection. Failure in any one of these causes the feature to break.
The most common reason the translation is grayed out or inaccessible is that no translation engine is selected or configured. Subtitle Edit requires you to explicitly choose and set up the service you want to use in the settings.
If the feature runs but returns empty lines or fails mid-process, this strongly suggests an issue with the API connection. This usually means the API key has expired, billing is not enabled for the external service, or the API has reached its daily/hourly usage limit (Source 3.2, 3.4).
A final, frequent cause of failure is using an outdated version of Subtitle Edit. Translation services constantly change their API addresses and security protocols; older software versions often rely on obsolete endpoints that are no longer supported (Source 2.4).
How to Check API Key and Billing Status for Connection Errors?
For paid or advanced translation services like DeepL Pro or Google Cloud Translation (V2), an invalid key is the single most frequent cause of connection failure.
If Subtitle Edit starts the translation but returns an error message like “Permission Denied” or “Invalid API Key,” you must verify your credentials and billing status with the service provider.
Verifying API Key Validity
Go to Options > Settings > Translation. Locate the section for your selected service (eg, DeepL or Google V2).
Carefully check that the API key entered is correct and that no extra spaces or characters were included during the paste operation. Even a single character error will prevent the connection.
Enabling Billing (Crucial for Google V2)
If you are using the Google V2 service, the error “Perhaps billing is not enabled” is common (see Sources 3.2 and 3.4). You must log into your Google Cloud account and enable billing for the translation API, even if you are using free credits. The API requires an active payment method for authentication.
How to Update Subtitle Edit and Plugins for Connection Stability?
If the translation feature has worked before but suddenly failed, the API endpoint may have changed, requiring a software update.
Outdated software versions contain obsolete code that attempts to connect to old server addresses. Updating ensures you have the latest API protocols and bug fixes necessary for a stable connection (Source 2.4).
Checking for the Latest Stable Version
Go to Help > Check for updates. Install any new stable version immediately. This often resolves translation failures instantly by updating the connection protocol.
Updating Translation Plugins
If you are using a third-party translation plugin (such as an older version of DeepL), go to File > Plugins… and check for updates for that plugin. These plugins handle the communication logic and must be kept up to date to meet the API’s requirements (Source 2.4).
How to Troubleshoot Network and Firewall Blocks?
Network security settings on your computer or router can silently block Subtitle Edit from accessing the external translation server.
The translation feature requires continuous internet connectivity. If your firewall or antivirus software detects this as suspicious outbound traffic, it will block the connection, causing the translation to fail.
Allowing Subtitle Edit in the Firewall
Temporarily disable your Windows Firewall or any third-party antivirus program, then attempt the translation again.
If the translation succeeds, re-enable the security software and manually add an Exception or Allow Rule for the SubtitleEdit.exe application to permit it to access the internet freely.
Bypassing VPN or Proxy Settings
If you are using a VPN or an external proxy server, try disabling it. Some proxies filter API requests or introduce latency, which can cause the translation process to time out and fail before the data is returned (Source 1.1).
How to Fix Grayed-Out Translation Options
If the Auto-Translate option under the Tools menu is completely grayed out, the software has not yet been configured to use any API.
The software requires a defined source and target language to proceed. This is a configuration error, not a connection error.
Setting Up the Default Engine and Languages
Go to Options > Settings > Translation. Explicitly select a basic engine, such as Google Translate, from the dropdown list.
Set a “From language” and a “To language.” This action enables the feature by providing the parameters the tool needs to function.
Checking File Status
Ensure a subtitle file is actually loaded in the main window. Subtitle Edit will keep the translation option grayed out if the editor is empty, as there is nothing to translate.
Frequently Asked Questions About Translation Errors
Why does the translation start but return blank lines?
This is a classic API block limit or timeout error. The solution is to switch the translation mode to “Translate each line individually” in the Translation Settings. This sends smaller, individual requests to the server, which are less likely to be blocked or time out.
The translation feature is grayed out. How do I enable it?
The feature is grayed out because no translation engine is selected. Go to Options > Settings > Translation, select an engine (like Google Translate), and set the required “From language” and “To language” to activate the tool.
What does “Permission Denied” mean when using the translation?
It almost always means your API Key is invalid or billing is not enabled for the external service (Source 3.4). If using a paid service, check your provider’s dashboard to ensure the key is active and the account has usage capacity.
Will updating Subtitle Edit fix the auto-translate failure?
Yes, updating is the first step. Translation failures are frequently caused by outdated software that relies on outdated API addresses or security protocols that have been deprecated by the translation providers (Source 2.4).
Can using a VPN break the translation feature?
Yes. A VPN or firewall can disrupt the continuous connection required for the translation API, leading to timeouts and failed requests. Try disabling the VPN temporarily to see if the translation succeeds.
Is the error caused by having too many lines in the subtitle file?
Not directly, but a very large file increases the likelihood of a timeout during batch translation. If the file is extremely long, use the individual line translation mode to avoid this risk.
How do I check if my API key is the issue?
In the translation settings, verify the key. If you are using a key-based service, check the error_log.txt file in the Subtitle Edit data folder for specific error messages like “Invalid API Key” or “Forbidden” (Source 3.2).
What if I don’t want to use Google Translate?
Subtitle Edit offers several alternatives, including DeepL and other external services (Source 3.1). Go to Options > Settings > Translation to switch the preferred engine, but note that many alternatives may require a personal API key setup.
