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An edit-conflict occurs when a page is being edited by more than one person at the same time, and the attempted changes are treated as being incompatible with each other. One person attempts to edit the document, but upon trying to save the new version, another person has already modified the document in the intervening time period, thus causing a difference between the attempted edit and the already-made edit that must be resolved manually. The software will then generate an "edit conflict" error message.
If a significant amount of new text is involved, the editor who receives an "edit conflict" error message can cut and paste the new text into a note pad or similar program for further editing, or can paste that text directly into a newer version of the target page.