If you look at the lectionary results for Psalm 50:1-6, one of the hymns that comes up is "When Morning Guilds the Skies." I can't find the error on the text page, so I'm not sure where this is popping up from.
Only 2 instances had the word "guild" for that text:
https://hymnary.org/hymn/WAR2003/111, which I corrected to match the page scan and
https://hymnary.org/hymn/CHMC1927/172, which I did not correct since it has no page scan to confirm.
I corrected CHMC1927 because the first line had "gild" and the title had "guild." I'm pretty confident that the title and the first line matched in the hymnal.