Fixing Apostrophe and Backslash Issues in NextGEN Gallery Alt Text & Descriptions

Many NextGEN Gallery users, particularly those writing in languages like French, have encountered frustrating issues when using apostrophes (') in their image Alt & Title Text or Descriptions. This article explains the common causes and provides the most effective solutions based on community reports and resolutions.

Common Symptoms

Users typically experience one of two problems when using apostrophes:

• 403 Forbidden Error: When saving a gallery, the page returns a "403 - Forbidden" error, preventing any changes from being saved.
• Backslashes Appearing: A backslash () appears before the apostrophe on the published frontend of the site (e.g., "l'arbre" becomes "l'arbre").

Why This Happens

These issues are not caused by a flaw in NextGEN Gallery itself but are instead the result of external server security configurations.

1. ModSecurity False Positive (403 Error): The 403 error is almost always triggered by the ModSecurity module on your web server. This security software incorrectly flags the apostrophe (a single quote) in NextGEN's admin AJAX requests as a potential SQL injection attack. This is a known false positive related to an old ModSecurity rule (ID 77229500 or 229500).
2. Over-Escaping (Backslash Issue): The appearance of backslashes is typically caused by a server-level configuration that is "escap"ing the apostrophe character. This means a backslash is added to ensure the character is treated as text and not as code. In some cases, this was a confirmed bug in older NextGEN Gallery versions, but it has since been resolved in recent updates.

How to Fix It

Solution 1: Resolve the 403 Forbidden Error

If you are unable to save galleries containing apostrophes due to a 403 error, the solution involves modifying your server's ModSecurity rules. You or your hosting provider will need to whitelist the specific rule causing the conflict.

Action: Contact your web hosting provider's support team. Provide them with the ModSecurity rule ID 77229500 and ask them to either remove this rule or create an exception for your website. This is a safe request, as the rule is outdated and its removal will not impact your site's security.

For users with access to their server configuration, the NextGEN Gallery team has suggested adding the following to your site's .htaccess file:

<LocationMatch "/">
SecRuleRemoveById 77229500
</LocationMatch>

Solution 2: Fix Backslashes Appearing on the Frontend

1. Update NextGEN Gallery: First, ensure your plugin is completely up to date. The development team has addressed and fixed an HTML escaping issue that caused this problem in one of the previous updates.
2. Clear Caches: After updating, clear all relevant caches. This includes:
   • NextGEN Gallery's image cache (Found under NextGEN Gallery -> Other Options -> Miscellaneous).
   • Any server-level or WordPress caching plugins you may be using.

Solution 3: Perform a Conflict Check

In some cases, other plugins or your theme might interfere. To rule this out, perform a standard conflict test:

1. Temporarily deactivate all other plugins except NextGEN Gallery.
2. Switch your theme to a default WordPress theme like Twenty Twenty-Four.
3. Test if the issue with the apostrophe persists. If it is resolved, reactivate your plugins and theme one by one to identify the source of the conflict.

Important Note on Alt & Title Text

It is not possible to leave the "Alt & Title Text" field completely blank. This is not a bug but a requirement for web accessibility (WCAG) and SEO best practices, as defined by the W3C. The "Description" field below it, however, can be left empty.

By following these steps, you should be able to use apostrophes in your image metadata without encountering errors or unwanted backslashes on your live site.