I've been encountering some oddities too:

occasionally out of the blue on a project that has run before, I'll get the message that my sound card is not supported at the configured sample rate. But if I keep on keepin' on.. it works.

I tried exporting ANY kind of audio.. WAV, WMA and MP3 ... and couldn't get any of them to work reliably when I merged all audio and midi to a stereo audio track. It took forever, and the resulting file would not play or even open in any audio editor. But, I could export individual tracks fine... just not a mix of all tracks. (but I need to do that a lot)

Sometimes when I reopen a project that worked fine last time it was open, as the song plays, it starts pausing in longer increments until the PC locks up. I mentioned this problem about a year ago, and that was on a different computer. Resetting to factory settings does not fix it. The only thing that fixes it is removing all track plugins then reapplying them.

I'm really good at causing my own problems by doing things incorrectly... but I don't see how I could be inadvertently causing any of these 3 problems. Yet, others are posting songs created in 2015, so they must be able to export their mixes.

I have applied the most recent patches... maybe I should try reinstalling from hard drive then update the patches

https://www.dropbox.com/sh/ey71h8ep047758h/AAC12jNM0Hz9Q8zsh5iDeqNHa?dl=0