Equalization (one-band customizable), Band-stop filter, Comb filter, Stereo-widener. They are successfully applying, but not reflected. Please, correct.
2.3.1-alpha-Dec 5 2016
Where are the plug-ins?
The same place where the rest:
C:\Program Files (x86)\Audacity\Plug-Ins
But the rest are reflected, and these - not. Why?
We appreciate your reports, but as we have repeatedly asked you, PLEASE tell us the exact file name of the plugin (for example, “widener.ny”) and exactly where to obtain the plugins you report. 
If you don’t do this, your report may be ignored, simply because we can’t find the plugins to test them.
Is it this Audacity download | SourceForge.net? It appears in History for me.
If those are “Bandstop.ny” and “widener.ny” from Missing features - Audacity Support they appear in History for me.
If that is “comb_1190.dll” from the Steve Harris swh plugins, it appears in History for me.
Tested on Windows 10 64-bit, “audacity-win-rf4a5805-2.1.3-alpha-17-dec-16.zip”, Audacity run in English or Nihongo as chosen in Audacity Preferences, or run in “System” Language with Japanese language chosen in Windows “Region”.
Gale
bandstop.ny, eqcustom.ny, widener.ny, comb.ny. But they don’t appear in history for me.
I take issue off. Excuse me.
Audacity 2.1.3 alpha ?
What does that mean? Was it “user error” (not a bug)?
2.1.3 certainly. Yes, it was my error.
Thanks for confirming. I’ll close this topic.