The source no longer includes this series on their release causing the discontinuance of the series in FRED.
The FRED series Total Credit Market Debt Owed by Domestic Nonfinancial Sectors - Nonfinancial Corporate Business is now known as Nonfinancial Corporate Business; Credit Market Instruments; Liability.
The source series id is FL104104005.Q.
This series appeared in both Table L.1 and Table B.102. For further information see the assistance provided in the guide to the Financial Accounts at http://www.federalreserve.gov/apps/fof/.
Board of Governors of the Federal Reserve System (US), Nonfinancial Corporate Business; Credit Market Instruments; Liability (DISCONTINUED) [NCBTCMDODNS], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/NCBTCMDODNS, July 25, 2021.