2000 Other BMW Models trans failsafe prog

Hi, on the last half mile of a 200 mile motorway journey the above message appeared on the dash display as I leave the motorway, a closer look later found what looks like transmission fluid or oil all over my drive and the underside of the car under the engine, also it feels like it is stuck in 4th gear, no problem with starting or overheating at all, also the dash display has started to fail on the same journey making certain words virtually un-readable not sure if at all related, the car is a 2000 523i se auto with 56000 miles & full history, could the problem be a pipe or hose has split, would really appreciate your help as I have only had the car one day and is now un driveable, thank you in advance for your time, Dave Kemp