Skype version 7.34.0.103
Skype works perfectly.

I just activated Replay Telecorder for the first time.
Replay Telecorder version: 2.3.1 - 09.10.16
Windows Version: 6.3 (Windows 8.1)
Windows sound setting: Realtek High Definition Audio (standard device)
enabled - Record remote audio (speakers) - Windows 7, 8, 10
enabled - Record local audio (microphone)
Replay Telecorder audio setup: Realtek High Definition Audio
If I change audio setup sometimes (conditions unclear) an error message appears: "Cannot setup recording graph"

Problem: Replay Telecorder does not record audio.
(It does record video, however, at least the Skype page, I have not tried a real video conversation)

Skype audio conversation works fine.
Replay Telecorder creates .wmv files as expected,
.....obviously with correct length,
.....file size makes sense,
.....files contain video
.....but files do not contain audio
tested with different players.

Question: How to get audio working?

P.S. "Audio setup - Tool - troubleshoot" produces an old and obviously obsolete help file. Please update. And please update the video tutorials as well.