After an Apex upgrade from 5.1.0.00.45 to 18.1 or after any dbcs patch upgrade, for example once the 18.2 patch has been applied:
# Setup again the ORDS certificate as discussed in this note.
# Reimplement the ORDS logging as discussed in this note.
# Optionally review the wallet and sqlnet.ora files
# Copy again the Apex 18.1 images