Happened to me on my 16 T120 at around 6000 miles. Transmission stuck in high gear and wouldn't downshift. No injuries to the shift mechanism that I could find. I was out of warranty so ordered all the parts myself and repaired it myself. Total cost with the clutch tool was around $100.00 US. I don't really trust the bike anymore so only ride it locally. There are a few of us who have had this issue with having no damage to the shift mechanism. Others who have had damage. There seems to be no rhyme or reason for this. But the shift mechanism seems to be NON robust. Personally it has put me off of Triumph. It is my first, I don't believe there will be a second in my future.