I recently encountered four (fairly recent uploads) downloads of split files (not rar) with par2s which NB normally handles with aplomb, that is, checking and joining.
After these downloads were complete (and I later watched the file parts download properly) I was left only with a .par2 and a .bat file - no file parts and no assembled file. The .bat file is NOT in the group listing but is (re)created as part of the .par2 recovery action.
I had thought using .bat files to assemble file parts to be a thing of the past. I presently have ".bat" and "[.]bat" in my download subject and filename exclusion filters to avoid accidently running these executables - which presumably is why it didn't show up in my header listings.
To bypass NBs auto PAR action just for these (four sets of) files, I downloaded just the files parts and assembled with HJSplit. I even managed to use a recovery file to verify the correctness of the files. The proper way I suppose would have been to deselect "autopar" and run the par2 manually, though I'm not sure that I would have noticed the .bat file was listed as missing.
Still, is this desired NB processing? It seems backward, I'm left with a .bat file and no parts or assembled file. Any way to delete the .bat file and join the parts if good? Or does NB still process properly even with the .bat file and I'm missing some setting to get it to do so?