After redacting text in a PDF, diagonal lines appear starting at the upper left corner of the page

Someone asked in a read-only forum about Acrobat adding thin diagonal lines to a PDF after performing some redactions. Since the question was not answered, and I just experienced the same problem, I wanted to post my findings and the solution.

The issue appears to be caused when the PDF was created by a program other than Acrobat, AND the PDF contains a table. When you redact any text in the table and apply, this is when the diagonal lines appear. Each line starts in the upper left corner of the document and ends at the separators between the table's column headings.

The solution is to simply print the original PDF to the Adobe PDF printer, thus creating a new PDF. Redaction worked as expected in the newly generated PDF.