The error code 4975 occurs when linking a Steam account to an EA account while launching an EA game via Steam.
This error indicates that EA's authentication servers have rejected the linking request due to security or eligibility issues.
EA's authentication tokens can expire or become mismatched with the current Steam session, causing the linking request to be rejected.
EA's servers reject the linking request because the token is considered invalid.
Author's summary: Fix EA error code 4975 by checking account settings.