I have uninstalled X-2 then reinstalled it. this is the message I sent to customer service, I tried calling but it's too late. I really don't want to not be ale to work all weekend because I can't get the metronome to work, I have checked the link someone kindly gave me but it does not address my problem. HELP!!
 TWO THINGS, first, I had to reinstall X-2 and when I open a project (new or existing) the dropdowns in the "use audio metronome" are blank. the db box's are fine and it sees my interface but there's nothing to select.
SECOND, when I start X-2 I get a message as follows "CAN NOT OPEN MASTER.INS. NO INSTRUMENT DEFINITAIONS WILL BE AVEILABLE"
please help me fix this.

if anyone wants pleas call me a 310 866 8096. i'm loosing my mind

You could try re-personalization. Start Sonar with the CTRL + SHIFT keys pressed, this will re-copy the files from "C:\ProgramData\Cakewalk\Your Version of SONAR" to your home directory including the metronome and Master.ins files.

scook, thank you so much sir (or madam) you have made my day. works fine now. and I don't have that annoying message anymore

You are welcome. For some reason the files that reside in "Your user directory\AppData\Roaming\Cakewalk\Your Version of SONAR" went missing. There is a metronome directory containing the wav files, the Master.ins and a bunch of other files necessary for SONAR. It is a copy of the the files located in "C:\ProgramData\Cakewalk\Your Version of SONAR". The re-personalization process described above copies the files into your user directory and resets some registry keys to their default values.
 
sc (a guy)

GREAT job, Mr Cook, and great news for the poster.
 
Bob Bone