My derailleur completely "opened" up. It is now almost a straight line. What have i done to my derailleur? I had a flat on the side of the road.  So I took my wheel off to replace the tire with a temp to get me home.  When I reinstalled the wheel, the derailleur &quot;opened up&quot; completely...what have I done/forgot to do? Can I fix it or is it done?
Figure 1. The way Shimano imagined it.
It looks like you have the first link of the mechanism mounted 90° clockwise. Try again.