Unable to create new project (invalid file line number 1)

I'm trying to create a new R studio project within an existing directory, but I receive an error message " "Project D:/.../TLS/._TLS.Rproj could not be opened: file line number 1 is invalid".

Oddly, I only receive the error for that specific directory.
Any ideas as to what would cause this?

Sorry for the premature post, but I'll post an answer incase anybody else has a similar issue.

It appears that I had already created an R Studio project in that specific directory in the past and then deleted it. Some of the files were still in the directory, which were hidden in Windows Explorer. I was able to create the project by deleting all the hidden files. In Windows Explorer under View, check the "Hidden files" box to view the hidden files.