I’m having the same issue and it’s affecting the performance of my site. I didn’t start having this problem until I updated to 4.3 on Monday, Sep. 7. If anyone could help us (myself and Romeon as well) figure out a way to fix this issue that would be great.
Let’s start with basic WordPress troubleshooting.
1) Disable all plugins and themes – just use a default WordPress theme.
2) Does everything work? Great. Then there’s nothing wrong with your WordPress installation. If not, re-install WordPress but make sure not to overwrite or remove the wp-config.php and the wp-content folder. Test and make sure a default WordPress setup works. If not, report back here and we’ll start some other troubleshooting techniques (look at error logs, etc.)
3) If the default WordPress setup works, great. Now we test your theme. Enable your custom theme and test your site. Does everything work? Great. If not, contact the theme developer for support as the issue is most likely with the theme.
4) If your custom theme works, it’s now time to figure out if a plugin is causing the issue. Enable a plugin and then test your site. Does everything work? Great. If not, contact that plugin developer for support. Follow this same technique for all your plugins. Enable one, then test the site.
By the end of this process you should be able to identify what may be causing the issue.
