server.error-handler-404="pihole/CustomBlockPage.htm"
2020-05-20 14:31:50: (response.c.404) uri-path does not begin with '/': pihole/CustomBlockPage.php -> 400
By comparison, the stock error handler appears as follows:
server.error-handler-404 = "/pihole/index.php"
Note that the block page will only be served for http sites, not for https sites.
The missing / helped. But now I'm trying to figure out the issue with Chrome wanting to download the page instead of displaying it. Will the PHP option work better?