Can't sell Business

I kept my car retailer for sale some days ago.
And now someone has given me an offer of buying it for g15,000,000.
I need to accept it but whenever I click the accept button it shows unable to buy business.

Thank you for bringing this to our attention, the error message is incorrect, we will look into it.
The player trying to buy your business can not purchase it as they do not have a business spot open for it.

ty for solving it