This fault sounds like you have to many schedules not enough recording storage.
Have a look at the schedule and see if you can delete a couple and then try and schedule your program.
Please let me know how you get on with this.
I have closed your other post so you are not double charged.
In order to provide you with details for delete the scheduled programs can you please advise the make and model of the recorder, and I will give you the require step by step instructions.