Partitions disappear when unlinking models, sites or trees in 2.6.3

[drdna]

Once you link models, sites and/or trees in BEAUTI 2.6.3 for OS X, it's not possible to unlink them without losing partitions. As an example, if I try to unlink site models for partitions NC and C2 in the attached images, I lose the NC partition identifier in the drop down menu.

Similarly, if you use parameter linking in the sites model tab, trying to unlink yields invalid options in the dropdown:

As a result, linking generates dead-end XMLs and one then needs to start de novo to try different parameters.

Also, is there a reason why BEAST has to be quit and restarted before one can upload a new XML for analysis?