I recently installed macOS Sierra along with JabRef 4.1 but to my surprise when I try to import files with the .bibtex extension (e.g., downloaded directly for APS journals) into my existing libraries, these files are not active in the JabRef Import dialog box. This is something I have routinely performed for years with previous versions of JabRef. Is there something I am doing wrong here? BTW, if I change the file extension for the same files to .bib, then JabRef is happy to import them but this is too fiddly to do for each reference. Please help!
i’m sorry, it seems like you stumbled across a bug - at least in the gui. As a workaround you could try
importing from the command line, that should work.
Another more simpler idea as workaround would be to associate the bibtex extension on your OS to open with JabRef