The Grid Code password is not a user-set password. It is a designed to prevent unauthorized or accidental changes to grid interconnection parameters. These parameters—like voltage limits, frequency trip points, reactive power settings, and islanding detection—must comply with local utility regulations (e.g., VDE-AR-N 4105 in Germany, G99 in the UK, IEEE 1547 in the US).
A quick Google search for "grid code password victron default" reveals dozens of frustrated forum posts. The most common speculation is that the password is: grid code password victron
By requiring a password, Victron ensures that only (licensed electricians or certified solar installers) can change these critical safety parameters. Entering the wrong grid code can cause your inverter to trip constantly, fail to export power, or—dangerously—back-feed onto a downed grid, risking utility worker safety. The Grid Code password is not a user-set password