Floating blocks wont print.

[Shadefreeze]

I've found out that floating there's some blocks that won't print. for example, floating slabs won't print at all if not connected to a full block.

[Neamow]

+1, have to place temporary blocks all over the place

[borjaxbox]

This is because as Litematica is mainly used for SMPs and other things like that it would be more like exploiting placing a block without support.

[JellyTale]

+1

It has nothing to do with it "mainly being used for SMPs." No idea where you'd even pull that fact from - Litematica is used for a number of purposes. It's entirely down to the "placeInAir" functionality being removed after the 3.0 rewrite. This is the #1 issue the mod is facing right now.