Wanted a little (not to much) challenge so I set up an IFR dusk to night flight from Denver to Grand Junction over the Rockies in my Seneca. All was going well. Had a great multi waypoint route set up in the Garmin. The fuel mixture/temp/airspeed was optimized. I was enjoying looking around with the drone. Then, when only 20 minutes out of Grand Junction, I inadvertently clicked on the vent window latch! Got the "Overstressed" sign and my flight was over!!!! :)