You’re using in_category()
outside of a loop, so you need to pass the post ID in as the 2nd argument.
eg, if (in_category( 'vid', $post->ID )) {
See Codex.
You’re using in_category()
outside of a loop, so you need to pass the post ID in as the 2nd argument.
eg, if (in_category( 'vid', $post->ID )) {
See Codex.