Can confirm this is an issue in 1.12 vanilla, not just with old version observer blocks, but even just observer blocks in general. I'm unsure whether they are stuck in that activated state or if they are just stuck in whatever state they we last in, being stuck on or off respectively.
Can confirm this is an issue in 1.12 vanilla, not just with old version observer blocks, but even just observer blocks in general. I'm unsure whether they are stuck in that activated state or if they are just stuck in whatever state they we last in, being stuck on or off respectively.