What is in the MRP Log before it dies?
as @Bart_Elia tells us. Did you check in the Flight Data Recorder for any clues.
If you have the sales order and part number from the log then you can look at all of the data behind it. If nothing else it will give you the job MRP wanted to make and you can attempt to make it manually. If it gives you the same error then you have more info to troubleshoot with. If you get the job made then MRP won’t need to make the job and should complete on the next run.