RMarkdown knitting remembers error, works if everything copied in a new file

I have an odd issue with RMarkdown PDF.
I have a file that was knitting without any problems. I added some changes and got some error. I reverted everything back via Ctrl+Z, but the error persisted. I reverted the file version, but it was still there. However when I copypasted the whole text into a new file, it run without any issues. I feel like this relates to this issue: r - RMarkdown - all cells run without error but when document is knitted errors occur - Stack Overflow

Is it some cache problem? Can I clear it somehow?

Did you set cache = TRUE ?

Does this happens when you Knit with the button or only interactively ?

I tried knitting by pressing the button only.
I see that I can clear cache via button (unlink('file', recursive = TRUE), I'll try it next time.

Where can I set cache = TRUE and how can I knit interactively?