Not able to update Performance template, even after associated performance doc Canceled and Deleted

Summary:

Not able to update Performance template, even after associated performance doc Canceled and Deleted.

I have run Process Mass Action for Performance Documents with cancel performance document

also Process Mass Action for Performance Documents with delete performance document

After that also I am not able to delete 'Document Period' form performance template, so that I can make necessary modification in performance document, but it is not allowing me to delete Document Period, giving error: 'You can't delete the document period because it's used in a performance document. (HRA-960149)'

Also showing performance template astemplate update process flag as Green check.