Board Thread:Questions and Answers/@comment-93.35.197.40-20150604215059/@comment-108.79.5.174-20150605000949

there can be a few things wrong. If any of the units are on a team they wont be allowed to be fused. If you favorited any of those units they will not be allowed to be fused until you unfovorite it. THose are the two reasons i know, i hope this helps. Good luck.