QT map problem - custom map

Hi. I have problem  with custom map on window 10. I don't see the tiles.

PluginParameter {

name: "osm.mapping.custom.host";

value: 'D:\maptiles\server\html\'

} 

PluginParameter {

name: "osm.mapping.cache.directory";

value: 'D:\maptiles\tmp\foobar4\'

} 

PluginParameter {

name: "osm.mapping.cache.disk.size";

value: "0"

}