Error generating PDF with RMarkdown

问题

I just bought a new Mac. I've cloned my git repo onto it, and ran the following, which worked fine on the old Mac:

rmarkdown::render(input = "statement.Rmd",
                    output_format="pdf_document",
                    output_file = paste(Payees$Payee[i], "identifying text", i, "2018_02", ".pdf", sep=''),
                    output_dir = "~/Desktop/path/to/directory")

I've installed tinytex on the new box, and I've run install_tinytex().

Here's the error I get:

tlmgr: package repository http://ctan.math.washington.edu/tex-archive/systems/texlive/tlnet (not verified: gpg unavailable)
[1/1, ??:??/??:??] install: ulem [10k]
running mktexlsr ...
done running mktexlsr.
tlmgr: package log updated: /Users/steves2018air/Library/TinyTeX/texmf-var/web2c/tlmgr.log
tlmgr path add
! Package pdftex.def Error: File `DATA/ART/UFO_Logo.png' not found: using draft
 setting.

Error: Failed to compile XXX_UFO_CL12018_02.tex. See XXX_UFO_CL12018_02.log for more info.

I'm sure I just need to install something. (By the way, I do use Homebrew, but I used the .pkg installer for R).

Can anyone give me a pointer? Thanks as always.

*Here's a link to the .log file referenced in the error msg: *

来源：https://stackoverflow.com/questions/49099813/error-generating-pdf-with-rmarkdown