I’ve had the same problem.
Ercan, are you running a plugin called The Events Calendar, by any chance?
No. I do not use The Events Calendar plugin.
I solved the problem as follows;
– I changed the name of plugin from FTP. Site opened.
– I deleted the plugin from FTP.
– I uploaded the latest version via FTP. The site did not open when you enabled it.
– I uploaded the old version from FTP. This time the activation failed.
– I updated the plugin from the admin panel. Activating failed. I deleted the plugin from the Admin panel.
– I reinstalled it from the admin panel.
– The plugin has been activated after repeatedly testing.
– It’s not connected to your jetpack account. After repeatedly tried, he was bound.
I solved the problem by trying very hard. š
By the way, my English is not very good. I do translation. š
Thank you for trying to explain how you solved the problem. I don’t think it’s your English, it’s me — I don’t understand how to use FTP in the way you describe.
Could you try to log in to your site via FTP or CPanel, delete the existing Jetpack plugin folder, and reinstall the plugin manually as explained here:
http://codex.wordpress.org/Managing_Plugins#Manual_Plugin_Installation
You’ll find the Jetpack plugin folder here:
wp-content
plugins
jetpack - DELETE THIS FOLDER
If you’re not sure how to do this, you can ask your hosting company for help. They should also have documentation explaining how to edit or remove files from your site using FTP or a File Manager in your admin panel.
Let me know how it goes.