2 Samuel 6:6 — Uzzah died near Nachon's threshingfloor
1 Chronicles 13:9–10 — Uzzah died near the threshingfloor of Chidon
These verses speak of Nachon's threshingfloor in one place and of Chidon's threshingfloor in the other even though both records are concerning the same incident. King David had conceived a plan for bringing the ark of God back to Jerusalem and while they were in the process of doing that, this incident happened and Uzzah died.
Since we are dealing with an identical situation, this cannot be speaking of two different threshingfloors. Furthermore, the wording of each passage in the text is also clear and there are no real translation problems involved. Thus there remains as a simple solution for this apparent contradiction the fact that "Nachon" and "Chidon" are the same person who is referred to in these records by two different names. Similar practise is seen also in other places in the Bible for other persons (for example, Peter is also called Cephas or Simon).