When I try to download a running-config, the Config Transfer Status shows the error: Connectivity issues discarding config file.
What does that mean?
No idea why it's not downloading your config. There is a way you can check why, though! In NCM, go to files, settings, advanced, session tracing and enable it. This will allow you to check a log file of what exactly happens when NCM tries to download your config. The log files will be in a folder specified in the window where you enable session tracing.
Good luck!
It's Cisco Catalyst 295048 G