As can be seen in release notes below, most of these are "Improves stability..." fixes.
Improves stability when creating dimensions.*
Improves stability when editing families*.
Improves placement of the site on Open IFC if the site is located away from the origin, or rotated.
Improves data integrity of a schedule instance on a sheet with the schedule view.*
Corrects the name of the Default Structural Area Reinforcement Schedule.*
Improves stability when attempting to use the Selection Box tool in Reveal Constraints mode.*
Improves stability when upgrading a model containing corrupt families.*
Improves stability when upgrading projects which may have some corruption.*
Improves stability when opening or upgrading a Revit 2015 project which contains stairs.*
Corrects an issue causing view filter names to be automatically appended when workshared models are synced.
Improves stability when editing selection sets in a workshared model.*
Improves data integrity of Project Address for upgraded projects.*
Improves stability when selecting a viewport with the Select by ID tool.*
Improves stability when canceling out of the view templates dialog.*
Improves stability when deleting an element which may have an invalid ID.*
Improves stability when using the Options dialog to log into A360 from a workshared central file.*
Improves stability when editing stacked wall types*.
Improves stability when cutting rooms to the clipboard.*
Improves stability when clicking Edit Preview in the wall structure dialog.*
Improves stability when editing the structure of walls.*
Improves placement fidelity with wire tags when upgrading a project.*
Improves stability when no panel schedule template is assigned as the default.*
Improves connection consistency of taps.
Improves visual fidelity of lighting fixtures within a copied group after the original group is modified.*
Improves stability when using Mechanical Settings.*
Improves stability when upgrading a project that contains user-created pipe types.*
Improves stability when opening a project which contains a Structural Isolated Foundation with an invalid analytical model defined as a column.*
Improves stability when placing a slanted column or a beam based on a Generic Model Line Based family.*
Improves stability after reloading an annotation symbol family used as a symbolic representation of brace elements on plan views.*
Improves stability when selecting a viewer element associated with Graphical Column Schedule.*
Improves stability when using Dynamo and the function: Select Divided Surface Families.*
Improves stability when DimensionSegment ValueOverride API is called when the dimension value was not overridden.*
Improves error handling with element's methods/properties.*
Improves consistency of UIApplication.PostCommand for pre-selection.*
Improves error handling with ElementCategoryFilter.*
Improves stability when editing families which use external resources for keynotes.*
Adds a validator to the Rotate Tap API to guard against creating invalid models.
Improves error handling with UIDocument.PromptToPlaceViewOnSheet() function.
Improves consistency of the RebarContainer element.*