Using an import statement where the jar is not in the /code folder generates an incorrect error
(red spew) message that suggests that the jar should be placed in the /libraries folder.

"Starting with release 0149, libraries must be installed in a folder named 'libraries' inside the
'sketchbook' folder."

In fact, creating a libraries folder inside the sketchbook folder does not solve the problem, the
jar must be placed in a 'code' folder.

No, if it's a library, then it needs to be in the libraries folder.

The 'code' folder is another way of using other JAR files that aren't
wrapped as a Processing library, but you're mixing two completely different
features.