So, I was testing out a frame quarry design in one of my test worlds. After running it a little bit, I noticed these strange blocks in the deployer. I'm not sure how I got them, but the items are called "Unnamed 762:1" This makes them seem to be a glitched type of Frame, since Frames have the ID 762. They look like an empty space in my inventory, except for the stack number, and the name bubble when I hover over them. Attempting to place them down only results in an Air Block and a temporary shadow.
While they don't seem to cause any crashes or anything, they do take up inventory space, and might cause problems if I get too many. If you know anything about this, it would be helpful to know how to prevent the creation of these. With the Deployer only having a Dispenser's inventory space, I don't want it to clog and jam the entire system. I while I didn't find many inside, I think it's better safe than sorry.