Objects with Invalid Symbol Type
Invalid symbol type means that an object is assigned to a symbol but object and symbol types are different.
They appear in the color specified in OCAD Preferences.
An invalid symbol type can occur for example if you change symbol sets of a map. If the new symbol has the same symbol number as the old one but the symbol type is different (e.g. an area symbol instead of a point symbol), OCAD cannot display corresponding point objects on the map anymore.
Or objects with invalid symbol type can occur if you delete a symbol (e.g. a line symbol) which is used on the map and then create a new symbol of different type (e.g. a point symbol) with the same symbol number.