PHP SDK stopped working

Error 504 usually indicates that the server did not receive a timely response from another server accessed while attempting to load the web page or fulfill another request.

1. Check Network Issues: Verify that your server has a stable and fast internet connection. Network issues can sometimes cause timeouts, especially when uploading large files.

2. File Size and Timeout Settings: Consider your upload file size. If the file is large, the upload might take longer than the server's timeout setting. If available, you can try increasing the timeout setting in your PHP configuration (max_execution_time in php.ini) and the client-specific timeout in the SDK.

3. AWS S3 Bucket Permissions and AWS Region - I assume it was not changed

4. Error Handling: Update your error handling to log more details. You can extend the catch block to get more insight into the problem. Here's an example of how you might expand your error logging:

} catch (Aws\S3\Exception\S3Exception $e) {
    // Catch an S3 specific exception.
    echo "AWS S3 Error: " . $e->getMessage();
} catch (Exception $exception) {
    echo "General Error: " . $exception->getMessage();
}

5. SDK Version: Make sure you use an up-to-date version of the AWS SDK for PHP. Sometimes, bugs or issues are resolved in newer versions of the SDK.

6. Test with a Smaller File: Try uploading a smaller file to see if the issue is related to the file size or the upload process.