All my cites seems to be working, except this one, and I can't figure out why — like all of my bibliography, it's exported from Mendeley, so I don't understand it isn't working… and now I'm out of ideas, so I hope that someone can help me :)
The code with the cite is:
The data in the table are obtained from~\cite{John2008}.
The warning is:
LaTeX Warning: Citation 'John2008' on page 5 undefined on input line 8.
This is the entry:
@incollection{John2008,
author = {{John, O. P., Naumann, L. P. Soto}, C. J.},
booktitle = {Handbook of personality: Theory and research},
number = {Chapter 4},
pages = {114--158},
publisher = {New York, NY: Guilford Press},
title = {{Handbook of personality: Theory and research}},
url = {https://www.ocf.berkeley.edu/{~}johnlab/bigfive.htm},
year = {2008}
}
I tried to remove the tilde from the URL, but that didn't help.
I use Biber and the \printbibliography-command to print the bibliography.

author = {John, O. P. and Naumann, L. P. and Soto, C. J.},– Ulrike Fischer Dec 20 '17 at 23:18