Need more info to guess: Which stage is your application? Initial assessment at CIO? Did you write all Personal Details of the family members (if you did not write 'Not Applicable" under the family section, they expect you to provide details). Note that if you are applying alone, you need to write N/A in all two sections reserved for family members.
In case you provided family details, did you fill in the Passport Details of family members?
Did you attach Photos to the application to CIO (You are not supposed to...)
Dear Albularyo I had the same NO PDT on the same section. I wrote in one section my spouse detail and forget to write N/A in other two columns and left them blank. They wrote same No PDT.Please can you explain did they return your application from CIO sydney .If so how many mistakes in your first app. Please explain