Right click on the working paper and from its context
menu select one of the options:
By default, only users who have a Reviewer access
level can mark a working paper as Checked.
If the Partner has marked a working paper as Checked, only they have
the right to unlock it and mark it as Not checked.
If the Manager has marked it as Checked, only they and the
Partner(s) can unlock it and mark it as Not checked, and so forth.
Only users who have a Full access level can unlock a working paper
once it has been marked as Completed.