It’s the most common error in Wordpress so everyone faces it once while working on it. You just have to make few changes in your application to resolve most irritated issue. You can check below for this:
- Check your .htaccess file carefully. For this you just have to rename the file and then run your website, if your website is working fine after renaming file then it means you .htaccess file is creating the issue.
- Increase PHP memory limit. You can increase the memory limit in wp-config.php.
- Deactivate all plugins. If above solution won’t work then you can deactivate plugin and then try again to access your website.
- Upload core files again.
- At last if all above methods are not working then you have to contact your hosting provider and they can help you in this.