library(tm)
vectorOfText <- c("twas brillig and the slithey toves",
"did gyre and gimble in the wabes")
names(vectorOfText) <- c("firstLine", "secondLine")
aCorpus <- VCorpus(VectorSource(vectorOfText))
produces aCorpus with a class of List of 2 - It should produce a VCorpus. At least, List of 2 is shown in the RStudio environment window.
However, class(aCorpus) executed in the console produces the correct class. For example
It's possible that this is a display issue specific to your installation of RStudio, or it could be related to the version of R, the tm package, or another package that you are using.
However, as long as the class() function correctly identifies the class of your object as VCorpus, you should be able to use it as intended in your R code without any issues.