In 1 Samuel Chapter 13 we find a genuine textual issue. They are not common, but here the age of Saul and the length of his reign is odd in the Hebrew.

This verse is translated in so many different ways. KJV: "Saul reigned one year; and when he had reigned two years over Israel," ESV: "Saul was ... years old when he began to reign, and he reigned, ... and 2 years..." NIV: "Saul was 30 years old when he became king, and he reigned over Israel 42 years." NASB: "Saul was 30 years old when he began to reign, and he reigned 42 years..." LXX: Simply left out. The number of theories about this verse are astounding.

What we learn elsewhere is that Saul actually reigned for 40 years. We get this from Paul in Acts