Copying redstone signal value from a different block

In my custom block, I have a procedure in the "Emitted Redstone Power" space that acts as a condition, returning the redstone power of the downwards facing block face. The issue is that whenever a block that accepts redstone power (i.e. Redstone Dust) is placed above my block, the game will crash. I've looked through the crash logs and gotten next to nothing out of it. Is there anything here that looks like it could cause a crash? My block does not tick.