Applying for Z Visa

Hello

I am a British citizen residing in Moscow, and am currently trying to apply for a Z visa as I have been given an offer of employment in China. Is it still possible to book appointments at the Visa Centre in Moscow? I have tried to book an appointment for several days, but it keeps saying that ‘the maximum number of people who can apply is 0’. Is there an issue with the website or are there no available appointments?
Thank you for your help!