Arduino Mega 2560 Mac Timeout

Hello Everyone,
I have an Arduino Mega 2560 that is timing out when I try to upload a sketch to it from my Mac. However I can do this fine from my PC. So I think the board is fine I'm new to Mac so I'm not really sure what I could be doing wrong.

Below is what I am seeing.

avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer

Thanks,

I installed FTDIUSBSerialDriver_10_4_10_5_10_6.pkg and its uploading now. However now every so often it crashes the mac. I didn't install the D2xx is this something that is needed and would this make my comp crash?

Thanks,