Make sure to create a plugins folder before you go to the WordPress backend of your site. Both plugins and plugins-old should exist in your FTP. The plugins folder will be empty.
Visit your WordPress backend, and login to check to make sure there are no plugins.
Now that you have renamed your plugins to plugins-old, and then created an empty folder named plugins, when you visit your WordPress backend, and navigate to the Plugins area, no plugins should be listed. This is where you know the plugins are officially deactivated. However, you need those deactivated plugins to show, so you need to go back to your FTP account.
Remove the empty plugins folder and rename the plugins-old folder back to plugins.
Go to your wp-content folder again, and remove the empty plugins folder. Make sure it is ‘plugins’ and not ‘plugins-old’. Rename the ‘plugins-old’ folder back to ‘plugins’. You need those plugins to show up in your WordPress admin after this step.
Go to your Plugins area in your WordPress admin.
All of your plugins should be deactivated. Don’t panic if your site looks weird. In fact, ignore it, as hopefully with this whole process, you should have your site working shortly.
Reactivate each plugin one-by-one.
Go ahead and activate each plugin one-by-one. After you activate the plugin, make sure no errors happen. If you get the screen ‘The site is experiencing technical difficulties” in WordPress, then that plugin was probably the problem.
You can deactivate that plugin by going to your FTP client, and finding the plugin in your ‘plugins’ folder. Rename that plugin by adding a suffix like ‘-old’ at the end. Your error in your WordPress admin should go away.
Remove or leave the faulty plugin deactivated.
If the plugin that caused the issue is one that you don’t use, just delete it. In the case you really need the plugin, you might want to let the plugin developer know about the error. However, if you can’t get a timely response, you may either need to hire a developer, or replace the plugin with one that has similar features.
In the case that none of the plugins were the issue, you should try switching your theme to a default WordPress theme like Twenty Twenty-Two.
Ensuring the integrity of your website
Once you’ve restored your site, as a precaution, to ensure that your site’s files are clean and free of possible malware, you need to use a malware scanner. If your site is clean, you don’t have to do much else except backup your WordPress website. If your site has been hacked and has malware, you’ll need to clean where the infection is located. If the infection is left, you could end up with the same fatal error issue, or worse.