Audacity Error Initializing Audio when I have USB audio interface on

A week ago I wasusing Audacity without any problems. Then midweek (Wed/Thursday) 11/11 or 11/12I launched Audacity and received the message "Error Initializing Audio.Could not find any audio devices. You will not be able to play or record audio.Error: Internal PortAudio error".
I read several postsin this forum and on www.tenforums.comthinking "what changed" did a patch come out? In the process ofreading and trying to figure out what happened. I did the following.
I am running Windows10 Pro 64 bit. I have been on Windows 10 now since the free upgrade in Augustwith no issues related to Audacity.
I was on Audacity2.1.0 and I upgraded to 2.1.1
I updated my RealtekHigh Definition Audio drivers to Version 6.0.1.7655 11/3/2015.
I saw one post aboutRealTek HD Manager not have the Default Format set. I checked that and it wasokay.
I have soundproduced through iTunes, Internet music streaming so everything checks on that.
Because I play musicI use Cakewalk Sonar and use M-Audio Fast Track Ultra USB audio interface. Idecided to power that down and to my surprise Audacity came up without the errormessage and it showed the Audio Device info.
I have notPersonally installed any new programs or updates on this computer except forwhat I mentioned above. I did notice that there have been some Windows patchesinstalled recently but nothing Windows 10 related. Just Printer, MS Office andWindows Malicious Software Removal Tool.
Have there been any patches lately that could have caused this?
Any thoughts?
Thanks

I posted this message on Audacity's forum site as well.

I have a Sonar Platinum studio (using a Roland Studio-Capture).

Normally (without any recording interface unit) Audacity defaults to the "Stereo Mix" (which should be set as the default recording device).

With my Studio-Capture powered on, Audacity on my Win 10 Pro 64 bit the default recording device is still Stereo Mix (see screenshot below). I used to have an M-Audio Fastrack Ultra 8R and don't recall the problem you are having.

I think Audacity is set to "default windows source" or similar and has problem to identify the source when your USB audio card is connected. Try setting it to a specific device from settings and then connect your USB. If it can start without issues you could then change the device to your USB.

@fireberd. I do have Stereo mix set as recording default. And this was working last week so I don't understand what changed.
@spapakons, I'm not sure I understand what you are suggesting. Could you re-phrase your statements.

I mean, if there are any settings inside Audacity, you can try setting the recording source to a specific device, not let it in "windows default". Then it should use this device even when you have your USB card connected without error messages upon loading. When inside Audacity with your USB connected you can then change the recording source to your USB.

Understood. If I have my USB audio interface connected and turned on, I get the error launching Audacity and there are no devices available to select.

If I turn of the audio interface I see the devices in Audacity.

Well, I haven't Audacity installed, so I cannot help you further.

I can't duplicate your problem with my Roland Studio-Capture. Audacity always defaults to the Stereo Mix when I start Audacity.

Thanks for trying firebird.

As I said before, try loading Audacity with the USB disconnected. Once there, look carefully at the settings/preferences/configuration (whatever is called). There should be a setting to select input and output source. Normally this is "windows default" or similar. Change it to a specific device so Audacity always uses this device ignoring any other devices. Close the program and connect your USB. Since Audacity now uses a specific device, it shouldn't search for other devices and give any error. Once successfully running Audacity with your USB connected you can then change the input and output to those of your USB from the same setting.