Sorry to bringt this up again, but since today (?) the (class_exists('\MBAC\Post')) request doesn't work anymore.
I'm wondering if Meta Box changed something but I think this isn't the case, because extending '\MBAC\Post' works fine.
Of course I could remove the (class_exists('\MBAC\Post')) request but I whish I can leave it for safty to prevent breaking the site if Admin columns isn't activated.
Does anybody know why this class_exists request doesn't work anymore?