I have two papers in my library with the same BibTeX citation key. Both have the same first author and publication year, but the additional two-character suffix at the end of their keys is the same (both “Olson2014-gz”). This is causing me problems when I try to use the exported .bib file with other software.
Hmm, we would have to investigate how this has occurred. The fix, however, is fairly simple: use the edit box to edit the citation key manually. You may have to use the “Additional fields” button at the bottom to reveal the citation key field.