Worst Concerts You Have Attended ??

I just left a remark about a favorite band of mine back in the day - April Wine - that I saw in concert and was disappointed. Could have been that it was an off night for them, or maybe they were never good in concert. Maybe the lead guitarist had too much to drink? April Wine was not the worst, however. I remember Neil Young in the 1990's who was on his one-man acoustic show type of tour that many artists were taking advantage of (perhaps for financial reasons) during that time. While a friend of I had near front row seats at Desert Sky Pavilion (now Ak-Chin) in Pheonix, the crowd was just roused up into a frenzy by the warm-up band (James) and here comes Neil and his guitar/harmonica. Wow, what a sonic letdown. I remember getting up and leaving and feeling Neil's glaring eyes on us as we ushered out. I think, to this day, he probably still remembers me. We all can remember the great live concerts we attended, but what were the worst and why?
Elton John in the the old concrete bowl international stadium in Baku, Azerbaijan around 2009-ish
Because he had to wait for the president who was over an hour late, to be seated I was already bored and annoyed. Sound quality was terrible, more likely the stadium rather than Elton John. Give him his due though, he did give his all. Tying for worst concert ever was Echo and the Bunnymen at University of Calgary. Just terrible all round.
Though not an answer to the question, the best concert I ever saw was The Clash in 1978 at Middlesbrough Town Hall in England. Never saw or heard such raw energy and crowd excitement before or since
What a great subject! I go to a lot of shows but these few come to mind right away:
Alice Cooper & Motley Crue 2014 in Glendale AZ. Worst sound I've ever heard. We couldn't hear the bands at all.
Aerosmith, Glendale 2005. It was towards the end of the tour and it seemed like they didn't want to be there
Van Halen, Glendale AZ, 2015. David Lee Roth can't sing anymore. My friend fell asleep.
Peter Frampton & B.B. King, Tucson, AZ 2015. B.B. was getting so old it was painful to see him try, someone should have pulled the plug. Frampton just love the sound of his own guitar. Not every song needs a 12 minute solo.
The best was probably Gram Parsons with Emmylou Harris and The Fallen Angels at Upstairs at Max’s Kansas City on March 7, 8, 9 of 1973. One night his friend Van Morrison? can’t remember if it was him or Tom Paxton, lol, was there and performed with him. I recall Neil Young and Linda Rondstat being present as well.

A friend worked the tables downstairs and she got me a front row seat (front row meant if you lean forward and rested your forearms on your knees, your head was over the front edge of the "stage") each night by letting me in through the backstage entrance before the show.
Speaking of bad concerts, am I the only one who absolutely abhors the fact that about a quarter of the crowd at any one time these days thinks it’s cool to pull out their cell phones and record for minutes on end? It takes a lot of enjoyment out of the experience to have dozens of lighted screens to look past to see a show. I’ve yet to attend an event where the no-filming rules are actually enforced.