: Ensure that the username and password correspond to the same product type . Some older licenses were product‑specific (e.g., only for ESET NOD32 Antivirus, not for ESET Smart Security). Using a credential on an incorrect product will always fail.
That said, many users and system administrators still encounter situations where a legacy product or a legacy activation method a username and password. The remainder of this article explains how to work around that limitation, either by retrieving the legacy credentials that were originally attached to the license or by using alternative activation methods that do not require the old‑style credentials. Eset Convert License Key To Username And Password