Richard Cockerill says Edinburgh's senior players must learn to "step up" after blowing their chance of reaching the Pro14 final with defeat by Ulster.
Edinburgh were 19-7 up with 20 minutes left, but conceded two tries as Dan McFarland's side drew level.
And the hosts gifted Ian Madigan the chance to slot the winning penalty in the last minute.
"I'm disappointed that we didn't understand what we needed to do," said head coach Cockerill of the 22-19 loss.
"Our international players in those key moments have to step up. It's about winning the game. It's about doing the right thing to win a game of knockout rugby and some of our boys clearly don't understand what that looks like.
"I won't make excuses and say we're on the right path. We should have won tonight."
Stuart McInally and Darcy Graham crossed for Edinburgh, with Rob Lyttle hitting back for Ulster. Chris Dean scored Edinburgh's third as the home side looked to be closing in on victory.
But a late collapse allowed Ulster to respond through Rob Herring and John Andrew, and when Michael Willemse was penalised for a deliberate knock-on in the 80th minute, Madigan showed nerves of steel to knock over from 40 metres.
"We got ourselves into a winning position at 19-7 and we weren't capable of controlling the game and doing the basics well enough to go on and win," Cockerill told BBC Radio Scotland's Sportsound.
"We got what we deserved. In the key moments some of our guys made some really poor decisions. We've got to get this better because this isn't good enough. We should have had the wherewithal within us to win."