Yes, many other have posted about problems but this is the 1st time I have had to deal with it :(  UUUGGGG  I've been trying for over 15 minutes to post a reply to Henna re her post on which cake mix recipe to use for the Wilton's Lg cupcake pan.  hOPE THIS TRY WORKS!!

I have found one does not need to add that extra 1/2 cup mix from another box.  Just follow the recipe as it is posted and it turns out just fine even with the smaller weight boxes of mix. 

Sorry the problem has now struck you, Lynne!  This is such a wonderful Forum, it is such a shame it has major problems.