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

Delete any .LXK files present. Do not worry – these are copies, not your original license.

Also check:

Now, open License Manager and re-add your original .LXK file.

Restart Proteus.

This forces Proteus to create fresh, uncorrupted registry entries.

Add the following to your Antivirus/Firewall exclusion list: Delete any

Right-click the ISIS Professional shortcut and select "Run as Administrator." If this resolves the issue, adjust the shortcut properties to always run with elevated privileges. Now, open License Manager and re-add your original

If nothing else works: