Have used Audacity 2.1.x and recently saves a user preset for 1sec under Generate-Silence. But when I select my user preset nothing happens. It doesn’t apply to the generate silence duration.
Have just DLed the latest Audacity 2.2.0 and thought I would try out the user preset again, but it still does not work. 
If there is a selection, then the “duration” setting in “Generate” effects is automatically set to match the length of the selection. If there is no selection, then the last used duration setting applies. This has been the behaviour since long before we had presets, so consequently the presets don’t affect the duration.
Is there a specific reason why you want a preset for generating silence?
I have the same problem in that presets for Silence seem broken. Using Windows 10, Audacity 2.3.2.
- I go to Generate > Silence. Then I chance to “seconds” and enter a number of seconds, e.g. 10.
- I go to Manage > Save Preset → I enter name, e.g. “10 seconds.”
- I check under Manager > User Presets that the preset names “10 seconds” is there.
Later, during editing, I go to Generate > Silence. The duration is set to what is apparently a default of 0.325 seconds. If I go to Manager > User Presets and select my previously saved “10 seconds” preset, the duration remains set at 0.325.
To answer the question you asked mystrt, I need presets because I am recording a series of oral exercises in Spanish, where there is an English spoken prompt followed by a pause for the user to respond in Spanish, followed by the correct Spanish answer spoken so the user can hear. I need the preset to insert a standard pause between the English prompt, user reply, and correct Spanish answer.
Thanks for any help.
You could generate the “standard pause” once and copy it, then for each other pause simply “paste”.
Thanks for your suggestions. This is what I started doing, just generating the pause once and then pasting multiple times.