Approve P/R is not available for creating P/O

HI,

User-A create a P/R and forward to user-B for review and user-B sent the same to user-C for approval via p/r approval hierarchy setup.

Once User-C approves the same the P/R forwarded to last approver for final aproval.

in the mean time user-C has resigned and marked as inactive user in system. So upon this the P/R neither show at last approver notification not coming to make Purchase order .

Now the view action history provide the status like that:

Action                             Performed by

================================

Approved                        User-C

Forward                          User-B

Submit                             User-A

Please guide, Thanks

Anwar