The temptation to use a crack is understandable, but it introduces severe risks that far outweigh any perceived benefit. A crack is almost never "just a crack."
Instead of searching for a crack, install the legitimate version on Linux (such as Kali Linux) by following these steps:
Instead of using a cracked version of Nessus Professional on Linux systems, consider the following alternatives:
Searching for a "crack" or "keygen" for Nessus on Linux is a high-risk endeavor. The files associated with these searches are frequently malicious.