GOG quit working - (file was corrupted and needs to be re-installed)

When I reinstalled GOG - my Witcher 3 GOTY is now in install mode in GOG.
game is still there - I just have to launch in a differnet manner .
Can I get GOG to see the game without doing teh install?

== IMPORT ALREADY INSTALLED GAMES TO GALAXY ==

1. For GOG games installed using installers from the last few months (so called Galaxy-compatible installers)
Click the Galaxy logo button on top of the sidebar and select "scan and import folders" - it will find all compatible games within that folder and add them to the Client.

2. For remaining GOG game INSTALLATIONS
Find the game in the Library (click on the image of the game), then click the More button and select "Manage Installation" -> "Import folder" and point the folder selector into the folder where that game is installed.

Source: https://www.gog.com/forum/general/gog_galaxy_beta_2/post1