Many users confuse the 20-character CD Key (needed for multiplayer keys) with the Manual Activation Unlock Code. They are different.
These answers worked inconsistently. Why? Because Relic printed three different manual revisions . If you use the wrong revision, you will get an "Invalid Code" error and be locked out after 3 attempts. Company Of Heroes Manual Activation Unlock Code
This process allows the user to verify their ownership by generating a "Request Code" (or Installation Code) based on their unique hardware ID and the serial key. This request must then be sent to the publisher to receive an "Unlock Code" (often stored as a license file). Many users confuse the 20-character CD Key (needed