How long has the lick been established?
Honestly, I wouldn't worry about it. I just put mine out yesterday (I don't care what they look like until right around now anyways). A lot of times, I don't see any descent bucks until around mid-August. On many properties that don't have many bucks on it during the summer, there will be more than average number of bucks show up right before peak breeding. We get a wave of "new bucks" around mid- October, then more at the start of November. We also lose some. Point is, if your not getting any bucks on cam right now, I wouldn't worry about it one bit