Basemap and OSM

I am new here and a scratching my head … I have recently moved to using a mac (macbook air) and therefore can’t/won’t use my map source programme anymore. I have downloaded Basecamp for Mac and downloaded a number of tiles from the osm source on the web. For some reason (and I don’t know which reason that is) not all tiles which i have downloaded (and installed, at least that’s what my laptop says) are not being displayed in Basecamp (to be precise anything west of Leeds/Sheffield and going further north in the UK is just a white area, only the basemap which is installed with Basecamp shows, no use for creating routes etc.

I have tried several attempts to download the tiles, no luck.

Any suggestion what i can do here?