This problem was solved as Russia was barred to use western's technologies. The MC-21 will be 100% indigenous.
As far as I understood in spite of western blockade Iran has been progressing in amazing way, it is certainly due to the persian's mentality, amazing persian's culture, that is far developed than all middle east's countries. A country that can develop F-5 E's jet's engine, will be able to develop one day an aircraft like the MS-21. It is simply a matter of time, because Iran is full of talents engineers, scientists, techniciains. And much among them could be considered as the best in the world. Amazing Iran!