@wp, database is informix, DataType of "Contact ID" field is ftString
@rvk, "The number in this cell is formatted as text or preceded by an apostrophe"
Excel finds out that Number is stored as Text and converts it to Number on double-click?
When I change cell Category from General to Text, green triangle stays on with the same error message, but double-clicking to it now do not cause display change to exp.