Formulas are returning #NAME? errors on opening workbook in Excel 365.

If I click on one of the cells, click in the formula bar, and press enter without changing a single thing, it works. The workbook has thousands of rows, and I am not doing that for every single one of them. Ctrl+Alt+Shift+F9 to refresh does not fix the problem. Is there a fast automatic way to force the calculations to work?