Image Import Errors

This document covers failures that can occur when the plugin downloads and attaches vehicle images from the AutoScout24 API. It describes likely causes and the steps to diagnose and resolve media import problems.

When to use this document

Read this document when:

• Vehicle posts are imported but have no images or only a partial set of images.
• The plugin log contains lines mentioning Image download failed or media_handle_sideload failed.
• The featured image is missing from imported vehicle posts.
• WebP conversion is enabled but images are saved in their original format.
• The image queue worker has been running but images are still missing.

Overview

When the plugin imports a vehicle, it downloads images from the URLs provided by the AutoScout24 API and attaches them to the WordPress post. The process uses WordPress's built-in download_url() and media_handle_sideload() functions, which place images in the standard WordPress uploads directory, generate thumbnails and register the attachment in the media library.

Deduplication

Before downloading an image, the plugin checks whether it has already been imported by looking for an attachment with a matching _as24ci_source_url post meta value. If a match is found, the existing attachment ID is reused and no download occurs. This prevents the same image from being stored multiple times.

Featured image

The first image in the set is automatically set as the featured image (post thumbnail) if no featured image is already assigned to the post. Subsequent images are recorded in the _as24ci_image_ids post meta array.

Image queue mode

When image queue mode is enabled (the default for cron and REST import runs), only the first image per vehicle is downloaded immediately during the import run. Remaining image URLs are placed in a persistent queue. A separate WP-Cron worker (as24ci_image_queue_process) processes this queue asynchronously in batches of 30 images per run. This reduces the time and memory required per import run.

See Cron Errors for guidance on diagnosing image queue worker failures.

WebP conversion

If WebP conversion is enabled, each downloaded image is converted to .webp format before being passed to the WordPress media library. The plugin attempts conversion using PHP GD (imagewebp) first, then falls back to Imagick. If neither extension is available, or if conversion fails, the original image format is used and a warning is written to the log.

Prerequisites

• API connection is working and images are present on the AutoScout24 listing. Verify this on the System Status page.
• The WordPress uploads directory is writable by the web server process.
• The Import images option is enabled in the plugin settings.
• PHP memory limit and execution time are sufficient for downloading and processing images.

Diagnostic steps

Step 1: Confirm image import is enabled

1. Go to the plugin Settings tab (or Import & Limits depending on layout).
2. Confirm Import images is enabled.
3. Note the Max images per vehicle value. If set to a low number (for example 1), only that many images will be downloaded per vehicle. Set it to 0 for unlimited.

Step 2: Read the log file

Open the plugin log file at:

wp-content/uploads/as24ci-logs/adp-car-market-hub.log

Search for the following patterns:

Step 3: Verify the uploads directory

The WordPress uploads directory must be writable by the web server. Typical location:

wp-content/uploads/

Check via FTP, SFTP or the hosting file manager that:

• The directory exists.
• The web server process has write permission (typically 755 for directories, with the web server user as owner).
• Sufficient disk space is available.

If the uploads directory is not writable, media_handle_sideload will fail with a file system error.

Step 4: Check PHP memory and execution limits

Downloading and processing multiple images in a single request requires adequate PHP memory. If the PHP memory limit is too low, image processing may fail silently or generate a fatal error.

1. Check Tools → Site Health → Info → Server for the current PHP memory limit and maximum execution time.
2. If the memory limit is below 256 MB for sites with large image files, consider increasing it via wp-config.php (define('WP_MEMORY_LIMIT', '256M')) or the hosting control panel.
3. For cron runs, the plugin attempts to set a 300-second execution time limit. If the hosting environment restricts set_time_limit, this may not take effect. Use the image queue mode (enabled by default) to spread image downloads across multiple shorter runs.

Step 5: Test image URL accessibility

If the log shows Image download failed with a network or HTTP error, verify that the image URLs returned by the API are publicly accessible from your server:

1. Copy an image URL from the log entry.
2. Try accessing it in a browser. If it returns a 404 or authentication error, the image may have been removed from the API or may require authentication that the plugin does not provide.
3. If the URL is accessible in a browser but not from the server, there may be an IP allowlist, firewall, or proxy restriction on your server's outbound HTTP requests.

Step 6: Verify the image queue status

1. Go to the plugin's System & Help tab.
2. Look for the image queue section showing: items remaining, last run time, processed and failed counts.
3. If items remain and the queue worker has not run recently, verify that WP-Cron is active and the as24ci_image_queue_process hook is scheduled. See Cron Errors for details.
4. If the image queue lock (as24ci_image_queue_running) is stale, delete it via WP-CLI or a transient management plugin: `` wp transient delete as24ci_image_queue_running ``

Step 7: Check WebP conversion prerequisites

If WebP conversion is enabled but images are saved as JPEG or PNG:

1. Go to Tools → Site Health → Info → Server and look for GD library and Imagick.
2. GD requires the imagewebp function, which is available in GD compiled with WebP support (PHP 5.5+). Confirm with your hosting provider.
3. Imagick requires the imagick PHP extension with WebP support compiled in. Confirm with your hosting provider.
4. If neither is available, disable WebP conversion in the plugin settings or contact your hosting provider to enable the required extension.

Configuration reference

Operational notes

• Images are downloaded with a 30-second per-URL timeout. Slow or unreliable external image servers may cause individual images to fail without affecting the rest of the import.
• Each downloaded image is registered in the WordPress media library as an attachment with post_parent set to the vehicle post ID.
• The _as24ci_source_url attachment meta value is used for deduplication. If this meta is deleted or corrupted, the plugin may download the same image again on the next import.
• The image queue can hold up to 20,000 items. If this limit is exceeded, a warning is logged and a deduplication pass runs. See Cron Errors.
• When all queue items for a vehicle have been processed, the _as24ci_image_ids meta is rebuilt from the actual child attachments and the images hash is finalised. Until then, the hash value is set to pending_queue to signal that the image set is not yet complete.
• Deleting a vehicle post permanently (via the plugin's delete function or from the WordPress Cars list) also permanently deletes all attached images imported by the plugin.

Troubleshooting

Related documents

• Troubleshooting Overview
• Import Errors
• Cron Errors