The error code 4975 occurs when linking a Steam account to an EA account while launching an EA game through Steam.
This error indicates that EA's authentication servers have rejected the linking request due to security or eligibility requirements not being met.
EA's authentication tokens can expire or become mismatched with the current Steam session, causing the servers to reject the linking request.
EA's servers reject the linking request because the token is considered invalid.
Author's summary: Fix EA error 4975 by checking account links and settings.