Solved my problem by checking the box “recompress all frames,” on the export page. Did not have to do this for other sequences, but this seemed to do the trick for the sequence that would not export.
Edward R. Murrow on Television
“This instrument can teach, it can illuminate, yes, and even it can inspire. But it can do so only to the extent that humans are determined to use it to those ends. Otherwise it’s nothing but wires and lights in a box.”