When in the past I have knitted an .Rmd file, it has automatically displayed the final pdf file using pdfLaTeX. Suddenly the display of the pdf file is no longer happening automatically. It's easy enough to display the file manually using Acrobat Reader, but one nice thing about pdfLaTeX is that it permits overwriting and reopening the viewer when I reknit the file. With Acrobat Reader I have to remember to close the pdf before reknitting.
Is there an easy way for me to reset the system to use pdfLaTeX to open the pdf files automatically following knitting an Rmd file?
Thanks in advance for any help.