Error message popup 'APP-OFA-48169 You cannot ' while I try to delete prorate conventions period

 the error message ‘APP-OFA-48168: You cannot delete this record because it is already in use’.

There are some Prorate Convention periods with wrong From Date, To Date, I am trying to delete the periods but probably some Assets have already been assigned Date placed in Service in the date, I have changed Capitalized assets' DPIS date outside of the periods but I still encounter the error message, Should I change the 'CIP' assets outside of the periods?

How can I delete the periods and correct the From to Date?