MCreator issue tracker has been migrated to GitHub.
Existing tickets have been migrated to GitHub. Please open new tickets on the GitHub tracker instead. If you do not have a GitHub account, all feature requests and bug reports from MCreator forums are still considered and checked by the maintainers.
You most likely have one model with the same name already imported. In the Java code, your model is called unknown. If you add another model with the same name, it will only overwrite the current one.