After my IT department has made some changes on this computer, I get the error "Invalid Key device! [0x013c8][c]".

Please open your file explorer to the ElecKey folder \Bin using Windows command-line cmd, and run ElecKey Integrator with the parameter /remakekey e.g.
EkInt.exe /remakekey
Or, you may create a shortcut to the above command. ElecKey will remake the Key with the updated hardware. Then, when running ElecKey again, you should see the registration dialog box, which you can enter your Activation Key to activate the license again.