Downloaded Schematica in 1.12.2, got the schematic I wanted, press "/" to open the menu and the schematics show up. The problem is when I click "done" to load one in, absolutely nothing happens. I don't have Optifine installed. I've tried in both single-player and multiplayer. Restarted my launcher multiple times and all of the works, still absolutely nothing.

Still having the same issue myself. No answers apparentlly

Im having the same Issue, any word on a fix?