How to deactivate a plugin when you are locked out of WP-Admin?
If you need to deactivate a plugin but you can't login to the WP-Admin, you can deactivate it via FTP by disabling the plugin's files. To do this, just follow the four easy steps below:
1. Go to your site's files and log in using an FTP program or the file manager that your webhosting company provided.
2. Next, navigate to the /wp-content/plugins/ folder.
3. Then locate the plugin folder that you need to disable.
4. Finally, rename the folder or simply add "-disabled" to the folder name. (e.g. askimet-disabled).
If the issue was with the plugin, you will be able to login again to your admin panel. You should get a notice that the plugin has been deactivated after you login to your WordPress site.