Oracle Solution for Error ora-29861

ORA-29861: domain index is marked LOADING/FAILED/UNUSABLE

What triggered the Error:

An attempt has been made to access a domain index that is being built or is marked failed by an unsuccessful DDL or is marked unusable by a DDL operation.

What should we do to fix it:

Wait if the specified index is marked LOADING Drop the specified index if it is marked FAILED Drop or rebuild the specified index if it is marked UNUSABLE.