i always tie external 1 to the volume block. if there is nothing attached to external 1, then the volume block will go to it's default setting of zero. the best thing to do is replace the volume block with a shunt, or un-attach external 1 in the volume block and replace it with whatever midi or analogue pedal you're using to control volume, as you'll need it for the "swells" patch. (if you're using a normal volume pedal in front of the axe, then just replace with a shunt)
you could make a quick change to the global settings, which will also resolve this issue and prevent it from happening in the future - go to I/O > MIDI and scroll down to where it says "ext ctrl 1 init value" and change this from zero to 100%
also, you'll find in the violin patch, i used ext 3 to control the "ensemble" feature. you can also use the initial value setting to virtually turn ctrl 3 on and off, by switching the value from zero to 100% for ext 3
hope that helps!
sim