My organization is using Alfresco Community v5.1.0. Recently, I have been experiencing a problem with the Model Manager. I had created two models. It gives a successful creation message and displays the model as normal. I then proceeded to create a property - and again everything appeared normal. Then it all suddenly disappeared - as if nothing was created. I refreshed the page, logged out and in again and still it did not show. I then proceeded to re-create the model. However, I was met with an error "We couldn't create a model as the model name 'xyz' is already in use.