From the beta list post for the newest build:

Mucked about with some of the XML output and the schema.

GCA will toss an error into the log when it sees duplicate tags for traits in books that are being loaded. (I will add an option to enable/disable this later; for now it’s enabled.)

Libraries that are changed in the library manager, and are also currently active in GCA, will now be reloaded when the library manager is closed.

The Modifiers button should now work consistently.

Clicking in one of the icon columns of the Classic View character trait lists should no longer trigger an exception.

Fixed some issues related to the Experimental option.

Updated some of the right-click menu options and handling in Classic View character trait lists.

Enabled cut/copy/paste in text boxes of Classic Attributes and Compact General Info.

Fixed an issue that created a fatal exception if creating a character, and the creation failed for some reason. (Any underlying issue still remains unfixed so far; this just keeps GCA alive.)