Looking at all the recent articles, we get a rough idea of what happened between the Karni Sena and the Padmavati crew.
According to the Karni Sena, it started off with RV's statement, coupled with the fact SLB refused to clarify the misconceptions early that led to this entire debacle (+ his track record too 😆). Add onto this, DP's tactless statements (and maybe the Ghoomar dance). I'm not sure if SLB promised to screen the movie for them but it is a possibility. He may have infringed on his promise.
According to the Padmavati crew, they have not shown any objectable scenes so they feel Karni Sena has nothing to be offended by. They perceive Karni Sena to be protesting needlessly.
While I do not agree with any of the Karni Sena's tactics and do not like how callously they are responding to the death threats, the main problem seems like the fact that SLB was not willing to engage in a dialogue and clarify all the misconceptions. The misconceptions, that came about (probably cos of the media), when clarified, were clarified late. While the Karni Sena had trust on them, SLB seems unwilling to communicate and now there's a loss of trust in SLB by the Karni Sena?
It feels sad that all the violence and anger boils down to simply miscommunication between Karni Sena and the Padmavati crew. Sometimes keeping quiet is not a good promotion strategy and this has blown up into all of this.