You've made an incorrect entry or incorrect selection somewhere is all. Work it through and make sure to read the small print on each and every screen. Hopefully, the below will help.
When/if asked how long the property was rented, select "the whole year".
When asked for days of personal use, that should be zero.
Percentage of business use should be 100%.
Days rented (only if asked) should be the number of days you had a renter contracted to be in there. Weather they were actually living in it or not, doesn't matter. They were "contracted" to be in it. If there was a vacant period between renters, that fine. Vacant days do not count against you. But personal use days "do" count against you, and therefore should be zero personal use days.
