Getting an error:

ChatterAnswersAuthProviderRegTest.validateCreateUpdateUser(), Details: System.DmlException: Insert failed. First exception on row 0; first error: REQUIRED_FIELD_MISSING, Required fields are missing: [ProfileId]: [ProfileId] Class.ChatterAnswersAuthProviderRegTest.validateCreateUpdateUser: line 31, column 1

While opening the Apex developer HTML guide it navigates to the PDF download page earlier it was html. please help to find that link. That html link was very helpful for us to learn online.

Getting challange while after creating Standard user'object field on Account  (pnone_UUID__c). it says field has nor created but i can see in my org.

error id: HZIAUZNH

 I want to count the number of opportunities for a particular date.

 I want to count the number of opportunities for a particular date.