--allow-newer-file

A 3MF file embeds the version of the application that created it. By default, if that embedded version's major or minor number exceeds the running CLI's own version, the CLI refuses to proceed and exits with an error. --allow-newer-file disables that gate: the version comparison is skipped entirely, and loading continues as if the version constraint were satisfied.

The version check is a major.minor comparison. A file created by a newer patch release (same major.minor, higher patch) does not trigger the gate regardless of whether this flag is set, because only major and minor components are compared. The flag is therefore relevant only when a 3MF was authored by an application with a strictly greater major or minor version than the CLI being invoked.

The flag is a boolean with a default of false. Passing it on the command line sets it true; there is no value to supply. Its scope is narrow: it controls only whether the CLI aborts on the version mismatch. It does not refresh, migrate, or validate the configs embedded in the file. If the newer-version 3MF uses config keys that the older engine does not recognize, those keys are silently dropped during loading; their effective values fall back to whatever is already present in the config from any previously loaded profile files, or the engine's own compiled-in defaults. The slice proceeds without any warning about which settings were lost.