According to TMZ, Juelz Santana was recently denied permission to travel to Miami due to a failed drug test. However, his team says it was a mistake. 

Court documents reveal that Juelz requested permission to travel to Miami for work but was subsequently denied after the feds stated that he wasn't fully complying with his release conditions. The mandatory drug test Juelz is subjected to revealed the Harlem rapper had opiates and methadone in his system. 

As part of his 27-month federal sentence, 19 months of which he was served incarcerated, Juelz is currently on supervised release. But the conditions of his release require him to remain in New Jersey unless a judge grants permission to travel. Not to mention, stay away from illicit drugs.

Another reason the request was denied was due to Juelz being in the company of two convicted felons, which violates the conditions of his supervised release. 

Source: tmz.com