Hi Folks

So the sun is out for the first time this year (UK!) so I decide to get the bike out for its first run. Got the whole day planned and disaster. As soon as I put it in gear she cuts out/jumps forward as though there is no clutch? Can't understand it she was fine when I put it away in November. I have started it regular over the winter months although never engaged a gear. Any ideas? the bike is like new only 2k miles and its an 2011.
Over the last few months I've fitted the Kev fuel mod, o2 sensor and DNA stage 2 filter and new pipes, Could this have anything to do with it? or side stand sensor? I'm kind of stuck....Thanks