Before 5.5, CacheFilter was not executed for requests initiated with the ERROR dispatcher, because CacheFilter extended OncePerRequestAbstractMgnlFilter.

In 5.5, CacheFilter does not extend OncePerRequestAbstractMgnlFilter anymore which causes the CacheFilter to be executed twice for example when requesting page that does not exist. Both executions share the same cache key so in the second request (initiated with the ERROR dispatcher) an empty response is returned.

This leads to error-pages (defined in web.xml) not working.

If CacheFilter is disabled or error-pages excluded from caching by other means, then they are working as expected.