There's no error code. Customer only sees the message "DRM license resquest failed" on LG TV WebOS 3.8 or above.
Just in case, first ask the customer to check if there's no system updates needed. If problem insists on occurring, it's because Internet Protocol version 6 (IPv6) is blocking the Disney+ app.
WHAT TO DO
How to prevent IPv6 from blocking the Disney+ app and fix the error message: