You want to compile a LaTeX file containing CircuiTikZ code but you get the following error:
Error: I do not know the key '/tikz/elmech'
First, be sure that the
circuitikz package is included, i.e. there’s a line like
in your LaTeX file.
If that is the case, you likely have an outdated CircuiTikZ version (
elmech is in TeXLive 2016+). Depending on your distribution, there are several ways to update CircuiTikZ: