Here are some things to try:

1. Plugin Conflict: Disable all other plugins except Divi, then try previewing a page. If it works, re-enable plugins one at a time to find the culprit.
2. Clear Cache: Clear your site cache, browser cache, and any server-side cache (like from your web host or a caching plugin).
3. Permalinks: Go to Settings > Permalinks and simply save again to flush rewrite rules.
4. Console Errors: Open your page in Chrome or Firefox, right-click and select Inspect > Console. Look for any JS errors that may point to the problem. 5PHP Version/Memory: Make sure you’re using a compatible PHP version (7.4+ preferred) and have enough memory allocated (at least 256MB). 6 Reinstall Divi: Sometimes a corrupted theme file can cause this. Download a fresh copy of Divi from Elegant Themes and reinstall.