I'm looking for a solution to enable redstone wiring (completing a circuit) by flicking a lever. If you don't know what I'm asking for, imagine that sticky pistons could push redstone dust, and flicking the piston on and off would push that redstone dust in the middle of two redstone wirings to connect a circuit together. (That example is just to explain the problem, I know that redstone wire can't be pushed)
One solution I thought of was to use a block in place of redstone dust to complete a circuit, but it seems to not work (the piston does not extend when powered).
Best Answer
I can see in your linked screenshot that you're using a slime block for some reason. Just a sticky piston on its own work work as well. And the slime block also tries to push the block below, which would push the block in front of that and in front of that and… It's basically trying to push an entire row of the world, which is much more than the limit of 12 blocks that pistons can push.
Just moving the piston forwards, replacing the slime block, would solve your problem.