Error: any other business income must be greater than 0

I have filled the Turnover space with my income, which is a lot less than £85,000, but I can't continue because of the error 'any other business income not included as a turnover must be greater than 0'. Why? I don't have any other income to declare, where is this coming from? Many thanks in advance for any help.

Hi,
If you have no other business income, the box must be left empty rather than have a 0.
Thank you.