add_image_size('excerpt-thumbnail', 658, 300, true); // Sets Index Page Thumbnails
add_image_size( 'themonic-thumbnail', 60, 42, true); // Sets Related and Recent Posts Thumbnails
add_image_size( 'ioslider-thumbnail', 658, 300, true); // Sets Slider Thumbnails
I changed the excerpt-thumbnail to the same size as ioslider, and then started the regenerate. I’ll fix the errors manually. One tip: turn off all the other plugins, and you won’t get so many errors! The plugin itself is very robust, and will pick up where it left off.