On Mon, Sep 17, 2018 at 10:50 AM Jacqui Coosner <jacqui.coosner@gmail.com> wrote:

Good day

Disclaimer: I am a beginner, and I apologise upfront if there is a simple answer to this question that I should have known.

Today I tried to compile an existing .tex file, and I received the following error message:

tex error on line 6 in file /Users/jjc/wrk/ctx/brx-test.pdf: ! String contains an invalid utf-8 sequence


As taco have said, 
your actions in the end are resolved in calling
context  /Users/jjc/wrk/ctx/brx-test.pdf
instead of (presumably)
context  /Users/jjc/wrk/ctx/brx-test.tex

--
luigi