I have the same problem
[404] /wp-content/plugins/tweet-blender/ws.php?action=cache_data
16:03:00 ->[404] /wp-content/plugins/tweet-blender/ws.php?action=cache_data
16:07:21 ->[404] /wp-content/plugins/tweet-blender/ws.php?action=cache_data
My blogg is at https://www.bahlool.se
