Why I cannot adopt cluster of NX5500 to VX9000? VX9000 has adopted couple of APs over MINT link level 2 and NX5500 is not able to adopt. No APs are adopted to NX5500. It is used just for tunnel termination.
If cluster of NX5500s is supposed to be adopted to VX9000, there must be no other MINT level 2 link than link to VX9000. Make sure cluster is formed using level 1 link and no other level 2 MINT link is there.