This is SO sad.
I wish I could give you some good news but I fear that there isn't any to be had.
There is an outside chance that the transmission linkage has come loose but probably not.
It also can be a sign of a very weak battery but if that was the case, it probably wouldn't start.
This most often is a sign that the electronics in the left handle bar cluster has gone bad (where the shift paddles are located).
The really BAD news is that many Can-Am dealers won't touch them if more than 10 years old.
Coupled with the fact that independent shops won't touch them even when new, this could be a REALLY tough situation.
I hope that you bought it from a Dealer so you can guilt them into looking at it.
But even that might not work because parts aren't easy to find after 10 years.
So, start calling around to any and all dealers withing 200 miles or so.
Then try other bike shops too.
I wish you luck.......because it is likely that will need it.
P.S. Your messages would be easier to read if you would format them just a little.
Like the white space in this post.