Although not the situation when you are trying to compile SHARC code using a Blackfin license, you can get this message even when you have a valid license.
The problem occurs if you have a floating license that can be used by multiple users over a network. Can be one of two reasons
1) Somebody else is using the license
Solution, give the guy some money to go for coffee so he / she can get the "CC 1548" message when they come back as you now have the lecense :-)
2) Network issues -- I am arunning a class where we have many flaoting licenses. When the network is busy, VDSP seems to time out when trying to access a license.
Solution: Just try again in a short while
Is it possible, as a user, to change this VDSP time-out setting (by a factor or 2 or 4)