New error when knitting get_engine(options$engine)

Question

I have an .Rmd file that previously had knitted without any problems. Now I am getting the following error when executing this instruction

confusionMatrix(prediction1, ssTesting$classe)

The error is

Error in get_engine(options$engine) : Unknown language engine 'test' (must be registered via knit_engines$set())

If I execute each chunk independently the error does not occur.

It only happens if I knit.

The error is independent of using version R-3.1.2 or R-3.2.1. I also set all the cache options to FALSE and made sure that all the libraries were correct but the error keeps appearing.

Answer 1

A simple typo in the beginning of the chunk ... ```{rtest.mod1} instead of ```{r test.mod1} Hard to see but simple to fix.