LaTeX.org

Uninstalling and re-installing LyX solved the problem.

I am new to Lyx and trying to import the tex file:

\documentclass{article}
\begin{document}
This is a Latex document.
\end{document}

I get the error:
An error occurred while running
tex2lyx2.3-f "TestLyx.tex" "TestLyx.lyx"

It seems too simple for anything to go wrong, but I must be doing ...