@e[c=1] error

/execute @e[type=Item] ~ ~ ~ scoreboard players set @e[c=1] Launch 1

When executing a /scoreboard command from an entity (such as an item), and putting @e[c=1] in for the selector in the /scoreboard command, the expected result is for the Item the command is being executed from to receive the score of 1 on the Launch objective.

However, it is the nearest player who has the command executed upon, not the item (or any other entity that is closer than the nearest player). Likely, the problem is that the c=1 argument is looking for the nearest player despite being an argument under the @e selector.