That sounds like the URL is not correct. Have you tried copying and pasting it into a browser to ensure you get the results you expect?
Be aware that if you are doing a reload in QV Server the service account may have different firewall/proxy settings than your own user account. Similarly, if you have connected to the server via RDP things could be different from when you are on your own machine.
(ooxml, embedded labels, table is [Bank Holidays]);
The first is a table in the middle of a web page, the second is a spreadsheet that is on the internet. In both cases if you paste what is in the square brackets into a browser you should get the data come back. QlikView can then interpret that.