syntax error t class

Why don’t you delete that plugin via FTP? That should get rid of the error, then you can re-install a fresh version of the plugin, but it’s probably the one that’s the culprit, so you may not be able to use it.

Yes, via FTP locate the following folder:

blog/wp-content/plugins/wp-responder-email-autoresponder-and-newsletter-plugin/

and just delete it.

All of your plugins are located in the plugins folders.