The first time you open an edited workbook in which the changes have been tracked, you might see no revision marks in evidence. In the Highlight Changes dialog box, the Since I Last Saved option is probably the culprit. For example, when editing a shared, change-tracked workbook, you might see revision marks appear on the worksheet as you work, but they disappear as soon as you save the workbook.

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To display all tracked changes
1. On the Review tab, in the Changes group, click Track Changes, and then click Highlight Changes.
2. In the When list, click All, and then click OK.