Originally Posted by
pandaperth
It's a bug - the tool seems to default to the "34,000 mile exceeded" error, when for whatever reason it cannot price up the itinerary.
In your particular itinerary there is an error, which will result in its failing to price up.
The error is that you have too many flight segments in Europe. You have five and you're only allowed four.
LON-LYS-LON-DXB-xDOH-LON.
ETA. I see danger and Dr. HFH posted while I was slowly typing my reply. 
In fairness I haven't been able to get the OW tool to actually price anything decent recently. ex-TYO, ex-OSL, and ex-CMB, all same result. I need to make friends with a travel agent but hate to have them pricing stuff just for the sake of it. I will definitely book another soon but trying to compare my options since I have zero expense ex-TYO, and it's a lot cheaper on miles to go to CMB vs. OSL.