This article provides a step-by-step guide on resolving the XML declaration error in the sitemap for search engine webmaster purposes.
Initially, it is essential to identify the root cause of this error. From my experience, this issue is often attributed to the presence of whitespace in a root file within the web directory.
While this tip is particularly beneficial for WordPress users, it is also applicable to other projects, especially the final method, which serves as a comprehensive solution for various websites.
In WordPress, certain plugins may not be well-designed, potentially altering web files and introducing whitespace that triggers the XML declaration error. Therefore, I will outline the steps to reset these settings to their default state.
For WordPress users, here are the initial steps to diagnose the causes of the XML declaration problem:
1.Install the WordPress Health Check plugin.
Activate this plugin and proceed to safe mode to systematically deactivate plugins, excluding the SEO plugin, to identify the trigger. Then, reload your sitemap.
2. Check PHP files in the root folder:
If the previous method did not resolve the issue, examine the index.php and config.php files. Remove any leading whitespace within these documents if it persists.
3. Review multi-plugin files:
As mentioned earlier, this error may be caused by certain plugins. If you suspect a multi-plugin issue, delete the respective folder containing these plugins to determine if the error is resolved.
4. Replace root files with new copies, excluding the ‘wp-content’ folder and ‘wp-config.php’:
If the above steps do not resolve the issue, it is advisable to back up your WordPress installation. Deactivate all plugins except for the SEO plugin and switch to the default ‘twenty-twenty’ theme. Delete all files within the root domain folder, excluding the ‘wp-content’ folder and ‘wp-config.php’. Download a fresh copy of WordPress and upload it to your root folder, replacing the deleted files. Refresh your sitemap, and the error should be resolved.
Recommendation:
The final method is effective for all types of websites and guarantees a 100% success rate for WordPress installations. This process is how to resolve the ‘XML declaration allowed only at the start of the document’ error. To prevent such occurrences in the future, it is advisable to use only well-designed plugins and limit the use of unnecessary plugins.”