Hey All. I've finally got a USB-Midi cable so I can actually start making music via keyboard. Before this I've had to manually tap the keys on the screen. However, in Sonar X1 LE the MIDI option recognizes the cable (otherwise the instrument/hardware) but when I click to accept it it refreshes the screen with the box un-ticked. I'm wondering whether anyone has knowledge of this? I'm new to all this, so I apologize if this is a simple matter.

which version of sonar are you using?  what is the make/model of the USB/MIDI cable?

when you click to "accept" where are you talking about exactly?  in the OPTIONS>MIDI DEVICES INPUT or OUTPUT? or somewhere else?

Hi, I'm using Sonar X1 LE at the moment. The USB Midi that I have is (I think - Mistar midilink - not sure this answers your question). It's got an IN/OUT port that is connected to the keyboard and a USB end connected to the PC. In the MIDI options in preferences, It appears, and It also appears as an output as well as Microsoft GS Wavetable Synth. I click the box in the Input, and it refreshes with the box unticked. I hope this answered your questions, and thank you. EDIT - To shed more light on the matter it appears in the MIDI Input/Output as Tahorng Musical Instrument.

I suspect there may be a problem with the drivers initializing in sonar for some reason. 

It keeps saying 'Undefined error'. Do you know any ways I can fix this?