Strasbourg won 2-1, as Tyrick Mitchell's opener for Palace was overcome by goals for the hosts from Emanuel Emegha and Samir el Mourabet.
Afterwards, Glasner told Palace TV: “It was a tough defeat, an unnecessary defeat. Our mistakes, our faults. We missed too many chances, we didn't decide the game when we should decide it, whether that’s in international football, or everywhere – in the Premier League it's the same.
“It happened just too often this season that we had so many chances, and we just missed them. We can't always rely on keeping clean sheets. Today we got punished for missing all these clear chances. That's why we are really not 'disappointed' today – we are really upset.
“It's our responsibility that the momentum changed. We took the lead, 1-0, and 30 seconds later it should've been 2-0. Then you get the momentum.
“Okay, they scored an equaliser because they were a very good team. We knew they were a quick team. And we had the next empty net in front of us, we missed it. Then we're one-on-one against the keeper, we missed it.
“It's our responsibility that we couldn't create the momentum more. That's why I think in the end we deserved to lose today.”
Glasner also sent a word to the Palace away support after failing to acknowledge them at the final whistle.
He said: “It was a great atmosphere in the stadium. Our fans were really loud. Thank you very much for the support.
“Sorry that I didn't come over after the game, but today I was too emotional. It really hurts today that we lost this game because again, we shouldn't lose. It's our mistake. If the opposition is clearly better and creates more chances, okay, then we have to accept it.
“But today we can't afford to miss so many chances, especially not in international games, and that’s why it really hurts today.”