Q:

Package inputenc Error: Unicode character α (U+3B1) not set up for use with LaTeX

When I compile the .tex file, I get the said error. It points out to .bbl file in the following line:
\bibitem{LIU20083883}
G.~Liu, T.~Nguyen-Thoi, K.~Lam,
  \href{http://www.sciencedirect.com/science/article/pii/S0045782508001199}{A
  novel alpha finite element method (αfem) for exact solution to mechanics
  problems using triangular and tetrahedral elements}, Computer Methods in
  Applied Mechanics and Engineering 197~(45) (2008) 3883 -- 3897.
\newblock \href {http://dx.doi.org/https://doi.org/10.1016/j.cma.2008.03.011}
  {\path{doi:https://doi.org/10.1016/j.cma.2008.03.011}}.
\newline\urlprefix\url{http://www.sciencedirect.com/science/article/pii/S0045782508001199}

How to overcome this issue? This error popped up in the new version of TeXStudio. I didn't see this while I compiled in the older version.

A:

You can edit the .bib file to read $\alpha$FEM, but there's a better method, namely loading textalpha.
\begin{filecontents*}{\jobname.bib}
@article{LIU20083883,
title = "A novel alpha finite element method (α{FEM}) for exact solution to mechanics problems using triangular and tetrahedral elements",
journal = "Computer Methods in Applied Mechanics and Engineering",
volume = "197",
number = "45",
pages = "3883-3897",
year = "2008",
issn = "0045-7825",
doi = "https://doi.org/10.1016/j.cma.2008.03.011",
url = "http://www.sciencedirect.com/science/article/pii/S0045782508001199",
author = "G.R. Liu and T. Nguyen-Thoi and K.Y. Lam",
keywords = "Numerical methods, Finite element method (FEM), Node-based smoothed finite element method (N-SFEM), Upper bound, Lower bound, Alpha finite element method (FEM)"
}
\end{filecontents*}

\documentclass{article}

\usepackage{textalpha} % <--- Greek letters in text

\begin{document}

\cite{LIU20083883}

\bibliographystyle{plain}
\bibliography{\jobname}

\end{document}

Note that the .bib file has to be slightly edited anyhow, because αFEM would result in

αfem

in print (and we can see it in your printout). The uppercase letters should be kept, so they should be enclosed in braces:
title = "A novel alpha finite element method (α{FEM}) for exact [...]

Also
pages = "3883 -- 3897",

should better be
pages = "3883-3897",

Note: I downloaded the .bib entry from the publisher's site.

