Breaking a block and spawns 2 entities instead of 1

In the block trigger "when block destroyed by player" make it spawn that entity, though you will need to change a few values since they don't always spawn the way you would want. I don't quite understand how it's spawning 2 entitles, if you could show the procedure I might understand the problem. 

You do not need the repeat block, the spawn entity will already spawn the mob, all it does is let you repeat an action without making 40 of them in a row.

do you have this inside the block broken by player procedure too?

If you have this as both block broken, and the block break trigger in the block triggers tab it will do both