Preview page in the new admin plugin

Hi, I Was just trying out grav as well as the new admin plugin. I can't seem to get the preview of the page editor to work. I edit a page, e.g. I'm at http://localhost:8000/admin/pages/test and when I click the 'eye' button in the editor, chrome devtool tells me that http://localhost:8000/admin/media/test.json/task:processmarkdown returns a 404 and the page shows me a red error panel.

I'm using php's built in web server. Everything else in grav seems to working, in case you suspect some url rewrite issue.

Please read this note regarding the PHP built-in webserver - It doesn't have the routing capabilities needed to support the admin plugin. You will need a proper webserver that has configurable routing support.

Just to be specific, the built in php webserver can't handle the : in the URI. It doesn't parse this properly, so any place we use these in URLs it will choke, hence the list of plugins that use that, and therefore don't work.

Ah, missed that. Thanks for the explanation!