Most "cracks" are bundled with malicious code. Since you often have to disable your antivirus to run a generator, you are giving Trojan horses, keyloggers, or ransomware a direct path to your hardware and personal data.
Altium Designer relies heavily on Altium 365 for component management and collaboration. A generated license will be blocked from these cloud services, leaving you with a buggy, outdated version of the software. altium designer license generator
"License generators" or "activators" found on shady websites are rarely what they claim to be. Here is why you should avoid them: Most "cracks" are bundled with malicious code