Either the safety is on or it was put on 'safe' before the bolt was inserted, i.e. the bolt was assembled wrong. I've had this happen before; in fact, I did this the first time I took my first rifle apart. IF the safety is on the notch will be at 12 o'clock. If it was put together wrong as described, the notch will be somewhere between 2 and 4. I can't really explain the best method to get it out when in this configuration. You've kinda just got to mess with it, pushing the safety and trying to lift the bolt handle.
Most recently I had a friend shoot my Type 99 and push and twist the safety while closing the bolt and this 'lockup' happened. Maybe I've always got lucky getting it apart?