InDesign script to invert the selection in InDesign document.
INSTALL INSTRUCTIONS: Unzip the JSX file to InDesign Scripts Panel folder (menu Window > Utilities > Scripts, then right click on "user" folder and choose to reveal in Explorer/Finder. Open the "Scripts Panel" folder). Saving the JSX file in this folder, it'll automatically be shown in Scripts panel inside InDesign software.
HOW TO RUN: To run this script you must have a document open in InDesign. With your document opened, go to Scripts panel (menu Window > Utilities > Scripts) and expand the "user" folder. To run the script, click twice on script filename. Running the script your selection will be inverted (unselected objects become selected and vice-versa).