Nav X error

My programming team has been running into an issue with the nax mxp libraries. We have been trying to use the robot example that comes with the c++ download for the imu. However after much difficulty with the libraries it is now throwing a single error on the imu inizilation. On imu = new IMUAdvanced(serial_port, 50); it says "invalid new-experssion of abstract class type ‘IMUAdvanced.’ " Do you guys have any ideas of what we might have done wrong or could otherwise fix this issue?

With the NavX, I believe you should be using the AHRS class. See the NavX docs: http://www.pdocs.kauailabs.com/navx-mxp/software/roborio-libraries/c/