[Jeffrey Clifton]

I know this is an old post but didn't see any fixes - here's what I did that worked on my z10. Clear cache as another user said by going to settings and clicking on version number. Then from the first screen in BBW click on icon that says All (lower left), then select My World. Select My Music from the menu that appears, this will take you to all your music purchased from BBW. Click on Albums at the top. The album that did not download successfully should have an arrow icon beside it instead of one that says Play like the rest. Click arrow to restart download of failed tracks.

If still doesn't work restart blackberry and try process again - seemed to be an error with my sd card that caused it because before I found the fix I went to file browser and it wouldn't populate contents of card. Restarting fixed that then I did the BBW process, so restart may be required.