The Button activation block used sometimes ceases to work and has to be replaced in order to have it be able to be activated.
Situation: Creating a rail lift system. Created a logic/rail control set of blocks (buttons next to rail blocks in a variety of directions, buttons connected in sequence.) Then copied and pasted this for each rail stop (not the most efficient, I know.) The first several have worked, but more recently I have had to replace occasional buttons because they no longer can be activated either by logic or by manually pressing on them.
(Using pickup rails not physical rails.)