Well that's not confusing at all.
I'm willing to test/debug this, but I need something to go on from. As I said, no logs, no debug output, no system log events. Procmon didn't help either. I did see that it opens a tls1.2 connection and data is exchanged, but I can't tell what unless the software dumps the plaintext to disk.

Started happening to me a few days ago. Some youtube videos work fine, for others svptube displays this error message and consumes 100% cpu.
301 is http code for a permanent redirect. Could be ad-related. I am unable to debug this because there are no log files and the error message is useless.