As discussed on the mailing list: Currently Hibernate ORM cannot distinguish between no BV provider being present at all and HV being present but failing to start during to the lack of EL libraries.

This causes no validation to kick in when using validation-mode="auto", without any apparent error message. We should raise a new dedicated subtype of ValidationException if EL isn't found (but required due to the usage or ResourceBundleMessageInterpolator). This allows ORM to handle that case specifically and propagate the exception when using validation-mode="auto" and HV is present but cannot be started.