Introduction

Following an upgrade to the program, a number of users have reported difficulty selecting various types of item.  This explains what's happened and how to recover.

Technique

There is a recently introduced function 'Select Mask' which allows you to deliberately disable selection of various types of structure - Components, Routing (tracks, connections and buses), Shapes (areas, board, shapes) and Text (text, names, values).  This function is controlled by each of four icons at the extreme right of the 'Edit' toolbar in pcb design mode.  Hovering over each icon should open a tooltip (if enabled) reminding you of its function.  The 'Edit' toolbar is normally the one at the right hand end of the row of toolbars at the top of the design window.
These icons appear as a row of four boxes with blue borders at the right hand end of the toolbar, so they're normally at the extreme right as you look at the row of toolbars.  When engaged (i.e. they are active) the border turns grey.  When active, they prevent selection of the relevant structures, so it can be very confusing if they are accidentally activated.
If you have a pcb design open but these icons are not visible, go to [Settings], [Customise] and open the [Toolbar] tab.  Check that the 'Edit' toolbar is enabled.  Assuming it is, if the icons are not present, it's possible that the toolbar simply hasn't updated correctly.  In this case, select the 'Edit' entry and click on [Reset].  If you haven't customised the toolbars, it may be simpler to just use [Reset All].  As soon as the dialogue is closed, the icons should becone visible.
If they do not all have blue borders, simply toggle any which are grey to re-enable selection of the relevant items.
If this doesn't resolve the issue, please contact the support desk.