Once an add-on is on my desktop (and enabled in Ext Mgr), how do I get it into my PS so that it appears in Esxtensions drop-down?

Question

I have acquired a couple of add-ons from the Adobe Add-Ons pages.  The icons are on my desktop, the extensions appear as enabled in PS 2014 Extension Mgr list (and are supposed to be compatible with 2014), but they do not appear in the Window/Extensions list in the program itself.  Do I have to move them somewhere?  or how do I use them?  In my previous experience with CS6 and CC did not encounter this situation.  I'd appreciate any help.  Thanks.
Gail.

Answer 1

I can no longer list extensions one by one with issues because, today,
every time I open Window/Extensions, in PS, either in CC-64 bit OR in CC
2014, the available extensions list changes.  The Ext Mgr also shows
different extensions at different times.  And not all the add-ons listed in
"My Add-Ons" as acquired and installed are listed in Ext Mgr at the moment.
For instance:  NOTE that I have had Russell Brown's Flypaper Textures Pro
on PS CC for a couple of years.  It has been there and working until today,
but now it is GONE.  This is not acceptable--I need this extension on at
least one version of PS.  It says it should be found in Windows/Extensions
in both PS CC versions.  A paper textures version--not the Russell Brown
one--was available for a short time this morning in the 2014 version, but
now it has disappeared.
What is going on here?  I can no longer even properly describe the problems
because they seem to be changing all the time.  These are not new or
untested extensions.  If they haven't been updated for 2014 (even though
they say they have), they should at least continue to work in the older
version.  I am about to restart my computer and each program to see what
the latest surprises will be.
I really would appreciate some help here, and I am sure I am not the only
one.
Gail