Until yesterday when selecting mates in Assemblies,  there was an orange preview of possible selections as I moved the mouse over festure/edges/'faces etc.  For some reason that is no longer working.  Now when I move the mouse cursor over possible selections there is no preview.  I  can still select but donw knot what  im getting until after selection is made.

Can someone tell me which setting(s) I’ve messed up to get the preview working again,

Thanks in advance