I have the same problem. Have used Magix Audio Cleaning Lab for about 8 months and suddenly it says I don't have a sound card installed [I do]. Right click on the red button and it scolds me,no sound card installed. Go to settings, go to the sound card line, and there's no sound card listed
Right-click on the speaker in the task tray, bottom right and open Playback devices. Check to see if your soundcard is listed. If not, it may be hidden. If you can click on configure, your should be able to show hidden devices. I can't, as the button is greyed out, for some reason. Do the same for recording devices. Make sure that they are available.
In ACL (I'm using AML so it may be different), top menu, Options, Playback parameters. Check to see if your sound card is there.
Right-click Rec (red) button for recording parameters, click on Audio input button, Audio input - what do you see. Open the pop-down. Is your external card there? If so, select it.
I have Magix Audio Cleaning Lab 2013 - 19.0.0.10 (DC2). This program works fine when I set the Capture format to MP3. Most automobiles CD players will not play MP3 files.
I decided to use the Wave capture format, but I struck a problem when it came to writing the Wave files to a CD. The program would not accept the Wave capture format but consistantly suggested this would be a MP3 format disk. The wave format could not be set to Wave.
Anyhow, I proceeded to continue with creating the CD disk. I could not check to see the size of the Wave files or how much room remained on the disk. This was totally in contrast to the creation of a MP3 CD!
I am starting to wonder if when I am importing from an LP I should tick the box "Save automatically into individual files"?