
And I'm going to bother you with some of my problems. Since long posts do repel casual helpers, I added some structure, so you can easily skip most of it.
First of all, I want to express my deepest respect. I do recognize a truly great piece of software, if I face one. The VoiceMeeter and "Banana" are something that should be bundled with every computer doing any kind of sound. I never thought, that my plain vanilla PC might be capable of THAT. This is just GREAT!
--- lament starting here ---
Being quite new in the field of recording, I did quite some research on both equipment and software and settled with a pair of CM3 Mics, a UR242 interface and VoiceMeeter along with Reaper for the recording. However, since running a full DAW to record a live performance of our orchestra seemed to be a bit too complex, I'd thought to give "Banana" a chance to do it all alone. A lean All-in-one solution capable of multi track recording.
Unfortunately life does sometimes infer with the best intentions. I did a couple of dry runs during rehearsals to make sure I get it right when I just have a few minutes to put up the mics, start the Notebook and off it goes. I found good settings for the buffer size that provides a clean signal, no loops, a signal limiter (just in case), so it SHOULD work in the field.
Well, it did not. I'm sure I am a dullhead that made some silly mistake(s) and not even really clever software as the VoiceMeeter can save me from (probably) doing something really stupid.
As I have learned, the "recorder" starts a new file every time, the "record" button is clicked. This is not explicitly stated in the manual, but quite what I hoped it does. On the set I had the chance to reassure me of this function on the performance of a couple musicians that performed before we were in charge. Every stop and record made a fresh file, so I happily did a final "record" just before we had to enter the stage.
As soon we finished, I stopped the recording and did a short rewind to check what I got.
--- problem description starting here ---
Well, I somehow managed to record our performance ON TOP of the previous recording into the same file

So what the f... has gone wrong there? A hidden feature? The entire recording unusable.

I DID have a Plan-B and had a Zoom Field recorder running - just in case, but that was a VERY unpleasant surprise.
Btw. the recording would have been crap anyway, as it was infested with pops and gargling all over. Nothing of this did appear in my tests and the headphone signal on the interface was clean by its nature. Obviously Windows 10 decided to do some work intensive maintenance tasks RIGHT NOW, when it had "nothing else to do".

I have a couple of indicators that make me aware of possible clipping but really none that can detect data loss? The "solution" is, to cross fingers that the tested setting will work the next time too? I always can check the record afterwards, but often I just have only one chance.
--- question starting here ---
So would anyone please enlighten me what I might have done to accidentally produce an overdub and if there is really no way that the system could give me a hint that there are buffer errors occurring while they are occurring. Just a hint would have helped me to be aware of the problem before it got catastrophic.
Thanks for listening,
smallfreak