There is a situation when in cache it is stored an 'empty' page. If you do a partial request to an URL that is forwarded because a virtualUri and cache has to store the request, then an empty page is stored in cache and next time that the URL is requested a blank page is displayed.

Steps to reproduce the issue:

1. go to http://localhost:8080/magnoliaPublic/.magnolia/admincentral#app:configuration:;/modules/ui-admincentral/virtualURIMapping/default and change "redirect" to "forward"
2. If you are working with travel demo, you need to remove personalization in root page in order not to bypass cache
3. flush cache
4. curl http://localhost:8080/magnoliaPublic/ -i -H "Range: bytes=0-20" > Expected 206 response
5. curl http://localhost:8080/magnoliaPublic/ -i > Unexpected 206 response (content is gotten from cache)
6. In the browser go to http://localhost:8080/magnoliaPublic/ and a white page will be displayed (content is gotten from cache).

I am not able to reproduce it in Magnolia 5.6, two registers are created in cache for this version.