BibTeX, biblatex and biber ⇒ warning: citation undefined

[emtimmers]

Dear all,
My citations are not recognized anymore when I compile my .tex file. My bibliography file is called encapsulation.bib and I'm referring to my bibliography using:
\bibliography{encapsulation}
In the main text I cite using (for example for a reference called "li") :
\cite{li}
What could be going wrong?

[Stefan Kottwitz]

Perhaps you have to run bibtex (or biber) again on the document, and then compile the .tex again.

Stefan

[emtimmers]

Perhaps you have to run bibtex (or biber) again on the document, and then compile the .tex again.

Stefan

What do you mean by 'run bibtex again'? I'm compiling my .tex file in Overleaf, with the corresponding .bib file in the same folder.

[emtimmers]

This issue has not been resolved, can somebody help me please? Thanks in advance!

[Johannes_B]

Are there any errors or warnings reported from Overleaf?