If you are trying to open LabTutor and the kuraCloud (Lt) Desktop app is open in your system tray, this could potentially cause a software conflict that will prevent connecting to a PowerLab. Quit the kuraCloud Desktop app, then restart your PowerLab and the LabTutor program to solve the software conflict.
If you still are experiencing issues after trying the above, please contact your localADInstruments technical support.