I have pulled the cable too tight before clamping and had the identical problem. (I used to pull the cable snug with a pair of pliers)
I have no idea what shifters etc. you have, but if you have a cable adjuster on it, back out the adjuster 1 turn so that you can add a bit of slack to the cable if needed.

You might also try backing out the L screw another 1/8 turn or so.