For the AB Tutor program to scan and find remote client machines, the Client program must not be running on that machine.
When you launch the AB Tutor Control Program, it detects that the Client software is running on the machine and asks you if you want to close it. For security reasons you cannot close the client program if you are not authorised to do so. Authorisation is done by checking that the connection password assigned to the Client program is the same as the connection password in the Tutor program. If they are not the same then you will get this message.
Please enter your normal Connection password into the Tutor program (See 'Tools' - 'Connection Password'), close and re-launch the tutor program. If you still get this warning message, then you have not set the correct connection password.