Knit is not working

Knit is not functioning.
Whenever I click on Knit. Nothing happens.
Nothing will print on the Rmarkdown panel.
The knit option is not at all working.
I had tried many solutions like creating a new project, reinstalling knitr package, resetting the Rstudio, reinstalling Rstudio, and many more...
But, the issue still pertains.
I had even tried knitting the sample RMD doc which Rstudio gives. But, failed.
Please, help with my issue. I'm new to the Rstudio.

What sort of code do you have in your YAML header? What sort of file do you want to knit to?

Blockquote I had even tried knitting the sample RMD doc which Rstudio gives. But, failed.

What error came up when you did this?

Nothing is printing anywhere.
no compilation, no error, just nothing. Complete blank.