How to prevent warning popup "...may contain feature not compatible..." when saving excel

[pstein]

When I open (in Excel 2007 under 64bit Win7) certain excel files , then change a text string in one single cell and save immediately afterwards the whole excel document then oftentimes a warning popup appears:

"foobar.ods may contain features that are not compatible with this format. Do you want to continue to save this format?"

If I click YES nothing errorneous happens.

So how can I permanently suppress for all future this annoying popup?

Peter

[Kyle123]

Can't you save it as an Excel file, ods is open office