After importing both files, selected second file by clicking Mute/Solo buttons on its Track Control Panel.
Chose Edit> Find Zero Crossings
Told to choose Edit> Remove Audio > Cut
Only available choice was Remove Special > Split Cut
All went blank.
I thought you had solved this and that “Lightroom Queen” had told you how to use Audacity Singles vs albums [SOLVED] 
No. Pressing Mute / Solo does not select the track. Click above the Mute / Solo buttons.
Sorry that is a mistake in the Manual - the item was called “Remove Audio” in the past, but it was decided to reorganise the menu. Use “Cut” which is near the top of the Edit Menu. The Manual has been corrected for the next version of Audacity.
You have to select the track. Most items in the Remove Special submenu require audio to be selected so they are greyed out if nothing is selected. Just use Cut instead.
Gale
Oooh!
She told me where to find the link i needed -not how to find stuff that’s screwed up, or not there!
So, till the next version comes out we have to come get the warm fuzzies from this forum!?
And where pray tell do you select the track? Maybe after you select ‘cut’ - which I had no way of knowing to do!?
I think that’s a pretty significant change that would be in FAQs! Show me where I missed it, please!
Listen, I appreciate the tough job you folks volunteer to do! Especially with newcomers that are frustrated and confused when they come to you looking for answers! Not chastisements for not knowing all the little nuance that lead you where you need to be! Just try a little more TLC!! I’m old, but I’m slow and a sensitive (but not always sensible) type guy!
You posted a link to How to Combine Songs on Your Computer Using Audacity. I assumed you found that easier to follow than our FAQ and were following that tutorial.
I apologised for that, but it can happen if decisions are made to change important menus. Nothing else is incorrect in that FAQ.
As the FAQ says, please take your computer mouse and click above the Mute / Solo buttons. You can click anywhere in that panel that is not a button or slider to select the track. For example, click where you see the “Hz” in that panel.
There are lots of ways to do what you want to do. If you don’t like cut and paste, take your computer mouse and click in the blue waves of the second track.
Press F5 on your computer keyboard. This enables Time Shift Tool.
Then take your computer mouse, and drag the second track rightwards until the start of that second track aligns with the end of the first track. You will see a yellow vertical line when the alignment is made. When you see that yellow line, you can release the mouse. Before or after the drag, you may want to use View > Zoom Out a few times so you can see what you are doing.
Press F1 to leave Time Shift Tool and go back to Selection Tool.
It’s a good job we are not sensitive. You seem to take every opportunity in Singles vs albums [SOLVED] to chastise us with multiple exclamation marks whenever there is something you don’t know how to do or don’t understand. 
Gale
I am a newbe and have just come across this Topic. may I hijack it for a second. I figured out that just a ‘cut and paste’ would join the tracks. Can you tell me, will all the tracks added, just show one title,ie, the original track all others are added to. I am trying to delete the track breaks added by somebody, who got it wrong by a few milliseconds. The track finishes suddenly, slight silence, then carries on and fades to the following track. Most annoying. If that makes sense.
It is generally better to start a new topic for a new question. It can quickly become very confusing when there are multiple questions in the same thread.
Very briefly; yes, all the tracks will become one file when exported and will show one title.
To add one other brief reply, if the tracks are files that have metadata like artist and genre, the exported file will have the metadata of the last file imported, not the original one.
Gale
Sorry and thanks. I am not to bothered about the one title, I was just checking. Main problem was the annoying break.
If you want to split a long recording into multiple files or CD tracks, see here: http://manual.audacityteam.org/o/man/faq_opening_and_saving_files.html#split