S1BTX: Can't coregister two S-1a images due to orbit file error

I would greatly appreciate help regarding two unresolved issues:

  1. Worldwind Map reports ‘No Network’ at the bottom right. I am guessing that this means that the toolbox is not able to connect to the Internet. However, when I conduct a Help>>Text connectivity test, the result states ‘Passed’. I have tried running the toolbox with and without a proxy but it still shows ‘No Network’. Any clue how to fix this?

  2. I am trying to coregister two images from S-1a and processing cannot go on due to the lack of the orbit file. I presumed that the auto download option did not work and hence downloaded the orbit files for both the images from https://qc.sentinel1.eo.esa.int/aux_poeorb/ and placed them in c:\AuxData\Orbits\Sentinel-1\POEORB\2015 folder. The TopSAR coregistration still reports that No valid orbit file is found. Any ideas on how I can fix this?

More information:
I am using the S1BTX version 1.1.1 on a 64-bit system with a Windows 7 OS

Thanks a tonne for your help!!