Technote (FAQ)
Command vmo returns with error nlist64 error 0
Kernel Mismatch
The error usually indicates the symlink for /unix is missing or incorrect..

# ls -al /unix

unix_64 --> 0 bytes

The solution for this problem is:

1. Force install bos.mp64 fileset
2. Restore the kernel file from a known good mksysb
3. Find a system in his environment which is at exactly the same level and copy the kernel over.