Contour matrix must be full. Contour matrix must be real. Contour matrix must have at most 2 dimensions. Contour matrix must have 2 rows. Text list values must be a vector or a scalar. Text list values must be finite. Text list values must be unique, sorted, and increasing. LabelSpacing property invalid with manual option to CLABEL. LabelSpacing property invalid when Contour handle argument to CLABEL is not specified. First input must be a valid contour description matrix. Not enough contour handles. Text handle output is not supported when a contour handle argument is supplied and label placement is automatic. The following text property is read only: {0}. The following text property will be ignored: {0}. The {0} property is ignored when a contour handle argument is supplied and label placement is automatic. Please wait a moment... Carefully select contours for labeling. When done, press RETURN while the Graph window is the active window.