Troubleshooting NextGEN Gallery Album Management Issues: Drag, Drop, and Performance

Many users of the 'Photo Gallery, Sliders, Proofing and Themes – NextGEN Gallery' plugin report a common set of frustrating problems when trying to manage their albums. These issues range from unresponsive drag-and-drop functionality to the entire 'Manage Albums' page freezing or failing to load, especially on sites with a large number of galleries. This guide compiles the most effective community-tested solutions to help you regain control of your album management.

Common Symptoms

• The drag-and-drop interface for organizing galleries within an album does not respond.
• The 'Manage Albums' admin page loads a blank screen (white screen of death) or a 500 error.
• The page becomes extremely slow or completely unresponsive, often timing out.
• PHP warnings appear, such as: Warning: array_merge(): Expected parameter 1 to be an array, null given in .../album.php on line 136.
• These problems often prevent adding galleries to posts or pages as well.

Why This Happens

Based on community reports, these problems typically stem from a few key areas:

1. JavaScript Conflicts: Modern devices, especially touchscreen laptops, can fire both touch and mouse events simultaneously, which can confuse the drag-and-drop code. Other plugins or themes loading outdated jQuery code can also create conflicts.
2. Scale and Performance: The 'Manage Albums' interface can struggle significantly on sites with a very large number of galleries and albums (e.g., thousands). The current design loads all galleries at once, creating a massive HTML structure that can crash or slow down a browser.
3. Plugin or Theme Conflicts: Incompatible code from other plugins or your active theme is a frequent culprit behind functionality breaking.
4. Caching Issues: Stale or corrupted OPcache or Object Cache can cause unexpected behavior in the admin area.

Recommended Solutions and Workarounds

1. Perform a Conflict Check

This is the most critical first step for diagnosing drag-and-drop and blank page issues.

1. Temporarily deactivate all other plugins except NextGEN Gallery.
2. Switch your theme to a default WordPress theme like Twenty Twenty-Four.
3. Check if the 'Manage Albums' page now works correctly.
4. If it does, reactivate your plugins one by one, testing after each, to identify the conflicting software.

2. Address jQuery Conflicts

Recent changes in WordPress core have deprecated older jQuery code. If the conflict check points to a jQuery issue, or if you see JavaScript errors in your browser's console, try this:

1. Install and activate the free Enable jQuery Migrate Helper plugin. This can often resolve compatibility issues caused by outdated scripts.

3. Clear Your Caches

If the problem is inconsistent or appeared suddenly, clearing various caches can help.

• Clear your browser cache and try again.
• Clear any server-side caching (OPcache, Object Cache). Using a plugin like Docket Cache can simplify this process.
• Clear your WordPress site's cache if you are using a caching plugin.

4. Check for a Known Good Version

Some users have found that rolling back to a previous version of NextGEN Gallery (e.g., version 3.41) resolves issues that appeared after an update. You can download previous versions from the Advanced View on the plugin's WordPress.org page. Always back up your site before downgrading a plugin.

5. For Large-Scale Sites: Mitigating Performance Problems

If you have thousands of galleries, the 'Manage Albums' page will likely remain slow or unresponsive until the 'Photo Gallery, Sliders, Proofing and Themes – NextGEN Gallery' team implements a UI redesign with pagination. In the meantime, you can try:

• Increasing Timeouts: Maximize the PHP max_execution_time and memory limits on your server to prevent the page from timing out during the long load process.
• Server Resources: Ensure your hosting plan provides sufficient CPU and RAM to handle the intensive database queries required to load all galleries.

Important Note: Directly modifying the ngg_album database table to manage albums via FTP or other tools is not recommended. The data structure is complex and tied to WordPress posts, making manual changes highly likely to cause corruption.

Conclusion

Album management issues in NextGEN Gallery are often solvable through systematic troubleshooting. Start with a conflict check, address potential jQuery problems, and clear your caches. For users with a very large number of galleries, be aware that performance limitations are a known issue, and the development team has indicated that UI improvements are being considered for a future update.