Can anyone help me with my icing problem?

The last 4 cakes I have done have not turned out good because my icing seems to melty (it looks as if it is breaking up in the bag). I am using the correct measurements for buttercream icing but can't seem to get it right.

I have never had this trouble before. My icings have always come out looking good.

It is VERY HUMID here in TN. Could this be a problem?

Please help.

Have you by any chance switched to the zero trans fat Crisco? I think it does produce a slightly softer consistency which might be more prone to melting, especially when it's hot and humid. You might try looking for a different brand of shortening that still has the higher trans fat content if you've been using Crisco.

It really sounds like the new Crisco which is awful. If you have an Aldi in your area, buy their veg shortening. It still haa transfats. (But read the label to double check.)