Users are unable to save secret questions or answers when they contain the '?' character. This article outlines the configuration required to permit the use of the '?' character.
Identity Manager 14.5 & 15
The '?' character is currently configured as a delimiter within the ForgottenPasswordHandler settings, causing a validation error when the character is used in user-defined questions or answers.
Note: The new symbol or character selected as the delimiter cannot be used in secret questions or answers.