Why am I unable to download Here maps via wifi?

[WPCentral Question]

Unable to download Here maps via wifi (lumia 630-cyan)

Hi,
I am trying to download netherlands map via wifi. It gets stuck as "Preparing for download" only. With data connection only, it says maps too large, use wifi.
Also, I tried to download a smaller region map via 3G, it worked fine and downloaded.

Can you suggest what could be going wrong with wifi download?

Thanks a ton for your help.

regs
subrat