Cannot Find A Valid License Key For Isis Professional On This Computer

| Cause | Likelihood | Severity | | :--- | :--- | :--- | | 1. Expired or Invalid License Key | High | Moderate | | 2. Windows User Account Control (UAC) Interference | Very High | Low | | 3. Corrupted License File ( LICENCE.LXK ) | High | Moderate | | 4. Network License Server Issues (Floating Licenses) | Medium | High | | 5. Antivirus or Firewall Blocking | Medium | Low | | 6. Multiple Proteus Versions Conflicting | Low | Moderate |

C:\Program Files (x86)\Labcenter Electronics\Proteus 8 Professional | Cause | Likelihood | Severity | | :--- | :--- | :--- | | 1