Before we fix the problem, we need to understand the enemy. Unlike a generic "Installation Failed" error, the E100 Exclusive code is specific to Epic's licensing system.
Do you have more than one Epic Games account? Perhaps you claimed a free game on an alt-account, but purchased the exclusive on your main account. The launcher sometimes gets confused and tries to validate using the wrong account's credentials. epic games product activation failed e100 exclusive
This is where Epic stores your login token and game entitlements. Before we fix the problem, we need to understand the enemy
For Epic Launcher version 14.x and newer (2023+): Older versions (Pre-2023):
Older versions (Pre-2023):