I work with a spreadsheet with about 600 rows. When I need to use a second tab most of the time It will crash . If I turn off compatibility mode it stopped happening. It will only happen when I close and reopen the spreadsheet. How can I keep it off unless I need it.

Hi dmatlof,

Could you tell me which version of excel are you using? And which version of excel did you create this file?

If you open a workbook which created in an older version, Excel runs in Compatibility Mode. In this mode, you cant use any newer functionality that your newer Excel version provides. This ensures that you do not add enhanced features to the document that people using an older Excel version cannot view.

In Excel 2007, exit Compatibility Mode by saving the file as *.XLSX (Xl2007 format) and reopen it.

In Excel 2010 and 2013, exit Compatibility Mode by clicking "File," selecting "Info," and then clicking "Convert." Excel converts the document into the current Excel format that matches the application version youre using.

Hope its helpful.

Regards,

George Zhao
TechNet Community Support