Errors when knitting RMarkdown to HTML (no graphs showing up in the HTML)

Question about knitting RMarkdown.

I am having issues when knitting a Rmarkdown file to HTML/pdf. When I run my chunks of code in the Rmarkdown file everything runs smoothly (and I get my graphs made with ggplot) but when knitting I get an output with no graphs and errors (error in eval, error in ggplot, error in print). Does anyone have experience with this?

—> I tried adding this in the beginning of my code but it is not helping

knitr::opts_chunk$set(cache=TRUE)
knitr::opts_chunk$set(echo = TRUE)
knitr::opts_chunk$set(error = TRUE)

Thanks in advance!!