It appears that the cdi extension in hibernate validator is calling getBeans() to scan for annotations. Based on the exception below this is not allowed at this time (during "after bean discovery" event)

I looked at the spec and the spec does not specifically say that this is illegal. Section 11.5.2 says:
"The container must fire a second event when it has fully completed the bean discovery process, validated that there are no
definition errors relating to the discovered beans, and registered Bean and ObserverMethod objects for the discovered
beans, but before detecting deployment problems."