A model cannot be simultaneously shared and used in multi-user mode. If you want to start using multi-user mode as a means to share your model instead of Tekla Model Sharing , you need to first exclude your local version of the model from the sharing service and then convert it to a multi-user model.
Note: The excluded model has no connection to the original shared model in the sharing service. This means that if you exclude your local version of the model from the sharing service and start to use the model in multi-user mode, you cannot later merge the original shared model and the multi-user model.