You should probably check with your license administrator to confirm that 1) Fixed-Point Designer is included in your license and 2) not all the licenses for Fixed-Point Designer are checked out.
It's possible the person in charge of purchasing the license didn't think any of their users would need to use that product and so didn't buy it. Or they may have bought only a few seats, expecting that only a few users at a time would need it, and that's no longer the case either temporarily (a short spike in usage) or long-term (more people becoming interested in using this product in their work.)
