Master Data Explorer disables Model and Entities after every action in Excel

I'm working with MSSQL 2014 and Excel 2013 with the Master Data Services Add-on (MSQL and Excel are both trial versions.)

When I connect to the model then I perform any action on an entity in that model, the Model and the list of Entities in the Master Data Explorer panel become disabled and I have to close the pane, reconnect to the MDS server and select the model again.

My MDS security settings are fine because I can edit the entities I want from Excel, it's just the disabling that is a pain. 

Is this the behaviour of the trial version? I haven't found anything that says it is.

Any advise appreciated. 

Thanks