Most notably Runic Altars, meaning you can't have a red string container under an altar, with an open crate on top to put items in (my current workaround is having a hopper to the side of the open crate, with the red string bound to that, but it looks really ugly)

The fix is probably to check if it can put in items (using IInventory or something) in here, but I'm not sure.

Its worth noting that the bug might be with Runic Altars, as you can't put items in with hoppers either (you have to drop them on top physically)