I've noticed that the 'over 34,000 miles' message can be entirely unrelated to actually having an itinerary over 34K. Everytime I've got the error message, it's been due to another issue that's easily rectified yourself. In my case, it's occurred where a direct flight wasn't available on the day I chose and the indirect flight causes the itinerary to have two many sectors. Or it's because business isn't available on all flights. Or it's because the tool has chosen a routing that arrives at one airport and leaves from another, again causing issues with the maximum number of segments. In all cases, I've been able to get rid of the error by reviewing each flight individually. In all cases, my itinerary is well over 34K.