Do you have 'Flag out of date symbols' enabled in DxDesigner (Settings - Advanced). With this option set the symbols to be updated should be highlighted on the schematic, then you use Tools - Update Symbols. If the properties still don't get added, check the settings for each property in the library to see if it is added to the schematic during placement or back-annotation (Property Definition editor - Place property in schematic... check box next to the property name).
Thanks for the solution. It worked for the new components to be placed.
But, for the already placed parts, it didn't work.
(Let me explain it.
I created a part (LED) and placed it. When I encountered errors, I updated the proprieties in the way you advised.
But the properties of the LED, which is already placed, didn't update.
But when I place the same part, after updating, for those parts,properties have been updated.
How can I solve the issue for already placed parts? )
If you are using DxDataBook with an associated part database then do a Live Verification to find parts that don't have the required properties and update from there. Otherwise a combination of Find/ to find the correct symbols and the regular Properties dialog will enable you to add the properties to all of the instances of the symbols.