Uncondiotional offer withdrawn by University citing administrative error

My son was offered the unconditional offer and then about 2 weeks later we got a mail saying that this was an administrative error!!! This offer was made after we submitted the class 12 mark sheet.I even submitted the relevant forms required for fees etc and the English language requirements. They now want him to take the foundational course! Can a university withdraw an unconditional offer? It is deeply disturbing and quite a trauma for my son and the family.

The uni can't withdraw an unconditional offer without your son's permission, (unless the info on his application is found to be incorrect, or the course is no longer running).

I would have him speak to UCAS about what the uni are asking him to do, (accept a FY offer).

One thing to consider is whether he is significantly below the requirements for the course, either in grades or qualifications. If so, the uni is offering him the FY because they think he will struggle with year 1 entry. There's no point insisting the uni takes him onto the main programme if he then either underperforms or drops out. In this scenario I would ask to speak to someone in the academic department about their concerns and clarify exactly why he isn't qualified to take year 1 yet.