Hey @senff,
Thank you so much for your helpful reply. actually their is the theme issue i get , when i updated my WP version this problem occurring from that time so could you have any idea how can i get solve this issue?
First Open your hosting account and navigate to /wp-content/plugins and delete that plugin or Try to Deactivate you plugin by renaming your plugin folder to plugin.deactive then finally you can login into wp-admin and again you can manage the unwanted plugins.
