How to make "white" jello using aloe vera jelly pack for broken glass dessert I've heard that it is possible to make the base of broken glass jello with aloe vera jello and milk/cream/vanilla ice cream. I attempted to do it but at first I brought milk to simmer then one pocket of aloe vera jelly but it got a lumpy mixture! At my second attempt, I did what I usually do with a packet of jelly and mixed together the jelly and boiling water until the jelly has dissolved and the mixture is smooth, let it cool. Then I poured milk to have the white color but the same thing happened. I wonder how should one add milk/melted vanilla ice cream/cream to a jelly mixture to prevent curdling? 

I wouldn't use unflavored gelatin, that's why I would use aloe vera jelly.
I have not seen this "aloe vera jelly" you describe, but from its behavior (clumps milk, needs a boil), it seems to be a pectin based thickener. If it is HM pectin, it will need enough acid, and this will clump the milk. 

The simple answer is that you will not be able to make a milk jelly with this thickener. Your options is to either use a different white liquid, or to use a different thickener. There aren't that many white liquids, but a nut milk might work. Especially if it's stabilized, it might not curdle under acid (but I'm not 100% sure). As for thickeners, you could try LM pectin, it will even get its calcium from the milk. Other thickeners are available, but the thickened texture will not be as gel-like, but have a somewhat different texture. Agar might work.