Malai Chicken Curry is curdling in the Pan
The cream and yoghurt will separate and curdle if you bring it up to a boil. If you cook the dish longer at a lower heat, you should be able to avoid this. Slow cooking will tend to make the chicken more tender as well. 

You need to keep the temperature of the yogurt below 190F (88C) to avoid having the milk proteins (mostly casein) react with acidic ingredients in the recipe and curdle. The acid comes from the yogurt itself and the ginger-garlic paste (most commercial, prepared ginger-garlic pastes have citric acid or similar as a stabilizer). You need to cook the chicken (and marinade because of its contact with the chicken) thoroughly, until it gets to up to at least 165F for food safety, but you do not want the sauce to get to 190F or boil. 

If you've made kadhi before (a curry from yoghurt thickened with chickpea flour), it is the same concept -- it will separate and curdle if you let it boil. 

Likewise, if you're making paneer from milk you want to get it close to boiling so that it WILL form the protein bonds when you add acid in the form of lemon juice or vinegar.