I was able to resolve this issue with the help of TAC, it was a mismatch secret. The error message in ISE was misleading.  May be a different issue for you, I pushed the config onto Nexus via DCNM. DCNM expects encrypted key to enter the config, whic...

Hi Glen, did you find your luck? I am facing the same issue with Nexus 9K switches with ISE 2.7, tried all the suggestions provided in this group. ISE logs " 13078 Invalid TACACS+ authorization request packet - possibly malformed packet " error.