I made several edits in my cinnamon.css file to change colour and other attributes. After scaling the learning curve, all went well BUT I didn't leave well enough alone and went back into the file to try to make a couple of more edits.

I obviously did something wrong because my desktop has reverted to pre-edits appearance. I thought it wasn't such a big deal because there aren't that many and now that I know how to do them, it will be easy to recreate.

However, when I re-open the cinnamon .css file, all of my previous edits are still there. They just aren't being recognized and displayed, either with Alt+F2 rt or with a restart. So, I can't run the previous edits and redoing them over top of what's already there doesn't work either. I have been doing all this starting with gksu xed in terminal.

Any clues? Thank you.

Cinnamon 3.2.7 on Mint 18.1

I'm guessing this would be related to the Cinnamon Control center. Have you tried reinstalling the control center with: sudo apt-get install --reinstall cinnamon-control-center or if you prefer aptitude: sudo aptitude reinstall cinnamon-control-center
If it comes back saying there will be issues or whatever, just quit.

@Brains: I ran sudo apt-get install --reinstall cinnamon-control-center. No issues at all.
However, the cinnamon.css file still contains the original edits that are not being recognized and displayed, and when I type over them to re-enter the edits, that is also not being recognized and displayed. My process here is:

Run gksu xed in terminal. Find and open usr/share/themes/Linux Mint/cinnamon/cinnamon.css Make the edits and click Save in xed. Run Alt+F2 rt to check the result, which is always that the default .css is running and the edited one (either original or as just now re-edited) is being ignored.

I'm running KDE, so I'm running a little blind. The cinnamon-control-center-data package may be the one that has the css file. Myself, since I symlink my apt lists folder and archives folder to the data drive, I keep all currently available packages in the cache since it don't bloat the /root partition. If I had the cinnamon-control-center-data package, I would right click on it and open it with Ark (archiver utility) and go through the data.tar.gz file and see if there is a directory structure like usr/share/themes/Linux Mint/cinnamon/ and in that cinnamon directory is a file called cinnamon.css, I would attempt a reinstall of cinnamon-control-center-data first, if that don't work, I would try copying the .css file from the package and place it in usr/share/themes/Linux Mint/cinnamon/, reboot and try editing again to see if it would take.

So...
If you have all the packages, look through them to see which installer package has the file you are having issues with. You can also use dpkg-query command to get the same information if you don't have the packages, see man dpkg-query

Thanks Brains. That was my thought too. If I had the original cinnamon.css file, I could just put it in place of what's there now and start over. I don't have the original installer package (or if I do, I don't have a clue where it might be). All I have is the a live USB of the entire Mint 18.1 download.

I'll check man dpkg-query and see what I can learn. Thanks.

You can also try apt-file to find which package would install it. "apt-file search cinnamon.css"
Have a look at this article.
If I had cinnamon I would run it here, but all I have is nutmeg.

OK so I ran apt-file search cinnamon.css. It returned about 12-18 different Mint themes that contain the cinnamon.css file. Are you saying that I could copy the cinnamon.css file out of one of them and place it in usr/share/themes/Linux Mint/cinnamon/cinnamon.css? Which get me back to a pre-edit version from which I could start over with the edits?

This would be a last resort, based on what you've mentioned, that the edits are not taking effect, suggests the file is being ignored somehow. It is possible a new default file was created, or some other default action by design took place that ignores the one you are dealing with. The route I would try first, is to reinstall the package that would bring it back to "as original/new state".
But, you can try that, just make sure to rename the existing file with .old at the end of it's name in case you get a major upset by trying this angle, this way you can reboot in single user mode and remove the .old extension and restore to previous state.
Also, if it is found in Themes, figure out what theme you are using and try reinstalling it.
Because hopefully, a reinstall also does a reset.

hmm.
you never actually tell us where that cinnamon.css file resides.

anyhow, i think you are trying to theme your desktop environment, right?
the proper way to go about it is thusly:
1) find a theme that kind of comes close to what you want
2) copy the complete folder to ~/.themes/ (that's /home/llewellen/.themes/)
3) rename the theme folder by e.g. adding -llewellen to its name, and the same for all occurences of the old theme name inside various files. this is your theme now.
4) choose your theme from cinnamon's gui theme chooser thingy
5) start hacking, re-apply 4) to see changes (you might need to change back to a different theme, apply that, then chaneg back to your theme, apply)

[SOLVED] I had made a few dumb typos when editing. With some good advice and handholding from others:

I downloaded the original Mint 18 themes and extracted usr/share/themes/Linux Mint/cinnamon/cinnamon.css
I then ran Meld to compare that file with my edited one and the errors were immediately obvious. Meld inserted the correct code from the original file and it all runs like a charm now.

Thanks for the helpful responses.

If you are going to work on themes, I suggest you start working in ~/.themes/

@Habitual: Lesson definitely learned :-)