I am not sure the Euro in itself was the problem, but countries where included before they where ready and not enough mechanisms across the union to help those regions/countries that where struggling. But,hey, I am but an armchair economist.
But for example Greece, that "cheat" they did to get in eurozone couple years earlier, wasn't a cheat back then and EU was totally informed, also the debt that swapped was insignificant compared with the amount of debt created due to systemic problems of eurozone and EU.
Too bad there are fake news only for the stronger, the weaker and smaller countries can do nothing but get crashed under the propaganda.