AVS2DVD - no longer makes DVD folders

Hi there, first post here and no expert on video software!
I’ve used AVS2DVD (current release) for ages to make discs from (usually) .MKV files - for friends (old) who can’t cope with media files. Suddenly (just after recent Win 10 updates) although DVD folder structure is selected as output format and confirmed by the last summary splash screen, it always outputs an M2V MPEG file. When source file is avi the output is correct - DVD folders.
I’m running AVS2DVD in more or less defaults mode - which has always been fine - making regular <4gb DVD discs and retaining original encoding format (usually NTSC).
I’m baffled by this problem. Installed latest KLite codec pack, which has always been fine. Tried various settings (and restored to defaults) but no good.
Suggestions appreciated.

Mr C has advised using the LAV filter package with AVStoDVD. I would remove the Klite codec package immediately.

Uninstall AVStoDVD and reinstall with your regular settings and the included LAV filters. I advise using a two pass encode with the HC encoder at all times.

Once you have your preferences set up, go to Codecs at the top of the main window in AVStoDVD, then Preferred DirectShow Codecs Setup. Set everything to LAV filters.

I’ll give this a try as soon as I can. Seems a bit counter-intuitive that the codecs would impact the output [I]format [/I]selected as opposed to just scrambling the output content (sync problems etc that I’ve seen previously.)
I’ll report back whether this or isn’t is a fix.

I’ve never heard your particular problem, so I’m trying a shotgun approach to fixing things. Codec issues are the most common for AVStoDVD, and many simply don’t know how to set up the LAV filters.

Uninstalling AVStoDVD might help if the program itself has become corrupted somehow.