vladasyn
I don't know when the blue squares on track number was added to Sonar. I have to check older Sonar releases. I only care about track name background turning blue- this is old Sonar way to select track. This is what I am used to. Being obligated to always click on track number is inconvenient because it is very small. I like to click on anything BUT the track number, because often if you click wrong way, all tracks (all 60 of them) get selected.

 
I understand how you feel - it is always difficult to adjust when behaviors change. Often I find though, once I get used to new ways of doing things I find advantages and wonder how I did things the old way! 
 
FWIW if you avoid clicking on track numbers as you say, you will certainly have dfficulty as that is the best way to ensure that a track is selected. If you single click on a track number only it is selected. If you double click will all tracks will be selected. 
 
Best of luck!

its all about focus. you may have focus on a certain track, but have selected another.
focus and selection are 2 different animals. once you figure this out, you wont have this problem ever again.
but like Squirebum mentioned, you can always click "Shift-Ctrl-A" to deselect all, then simply drag to select or cntl select multiple tracks to make your selections.

I always, habitually do a ctrl + shift + a before I do ANYTHING involving copy, cut, paste, delete etc
 
Consequently, I've never lost a single thing whilst editing.

I'll admit it: I, too, have accidentally deleted tracks in the past. At least one of those times, I didn't notice the mistake before saving the project. As a consequence, I am very, very careful when I delete a track.
 
Although this is rightfully chalked up to user error, safeguarding against it would be trivially easy. All it would take is a verification dialog that listed the tracks about to be deleted. It would, of course, be optional for those who are annoyed by "are you sure?" prompts. 
 
De-selecting everything first is the easiest preventative. But as a software developer I don't like to rely on what users can do to protect themselves. Calling it a "training issue" is a last resort. I look at what kinds of mistakes they are committing most often and see if there's anything I can do to help them out.
 
In my software, there is always a verification dialog and the default is "Cancel". You have to intentionally click "Yes" to complete the deletion. I don't stop there; the data is also written to an undelete log, and there is a utility that can find and retrieve that deleted data, months or years later if necessary. Since it's a multi-user system we also track which user did the deed, so that they (not me) will be berated by their bosses and co-workers.

vladasyn
...., but then the guitar track disappeared. This is just so wrong! This was guitar track that was recorded by sessional guitar player and I had to pay for it. I can not afford it to be randomly deleted and then have to ask him to come back and learn the song again.

As I'm sure you know, when you delete a track in Sonar, you have not lost the audio.  It still exists in your 'Audio Folder' AWA wherever you originally imported it from.
 
HTH

I assume you mean 'delete the clips in a track'? I just right-click the clip then hit the Delete key or select delete from the right-click menu.

"Disconnected" Focus vs Selected has bitten me more than once.  There are times where I find it incredibly frustrating.
 

Bristol_Jonesey
I always, habitually do a ctrl + shift + a before I do ANYTHING involving copy, cut, paste, delete etc
 
Consequently, I've never lost a single thing whilst editing.

In a similar vein, before recording I always check the Record button in the Control Bar and if it is lit, I click on it to clear everything before I select the track I want to use for recording.

+100 for shift + ctrl + A. This is such an essential shortcut to learn. Deleting a track is a serious business which should always be done with care. Doesn't matter what app you're using, "delete" will always delete the current selection and so it's essential that you check what that selection is before clicking OK.

Bristol_Jonesey
I always, habitually do a ctrl + shift + a before I do ANYTHING involving copy, cut, paste, delete etc
 
Consequently, I've never lost a single thing whilst editing.

Yes. THIS^^^^
 
Ctrl + Alt + Shift should be absolutely ingrained into your workflow and muscle memory. Even when I am about to perform a function where it does not matter if multiple tracks/items/whatever are selected I still do it... EVERY... TIME. I even do it AFTER I've completed my move just so nothing is selected as I do other stuff JUST IN CASE.
 
It goes like this...
 
1) I'm about to do something that involves selecting 1 or more tracks/events.
 
2) I hit Ctrl + Shift + A to clear all selections in the project. Sometimes I'll even do it twice to make absolutely sure nothing is selected.
 
3) I will make my selections then DOUBLE CHECK the selections so ONLY the desired selections are made. note: sometimes I find when selecting a single item it will select other items. I think do to a double click being registered or something extending the selection.
 
4) Once I have confirmed ONLY the items I want selected are selected do I make my move. I double check to make sure what I wanted happened and nothing else was affected (by either playing back and/or giving the GUI a quick visual scan to see if anything is out of place)
 
5) I'll hit Ctrl + Shift + A again to clear the selection so as I move to other areas of the project and continue working those selected tracks/items don't get inadvertantly affected.
 
 
All of this happens VERY quickly because I just beat it into my brain looong ago to be ultra vigilant about my selection(s) status (I have created some VERY heinous problems for myself in the past due to unwanted selections). It's second nature now. Certainly not ALL of that is necessary every time BUT what it does is create a procedural "redundancy" whereby if I happen to forget to do one or multiple items in that procedure the chances of me having an unwanted selection are vastly reduced.
 
Essentially the little bit of extra time I spend constantly doing that (might add 1 second to each move I make at most) I potentially save myself minutes or even hours of time trying to figure how to fix a screwup.
 
It's the same reason my project folders are FILLED with dated and properly named "Save As" versions. I don't "Save As" after every move of course but after I've completed a series of moves and the task I set out to do is accomplished (eg: I record a bunch of guitar takes, "Save As 1". I edit/comp/flatten the takes, "Save As 2".
 
Also in BETWEEN those "Save As" actions I use the regular "Save" function in case of a Sonar crash. That way instead of losing everything backward to my last "Save As" I MIGHT be able to recover the project up until my last "Save" action.
 
Also remember that if you "seemingly" lose audio files from your project you may be able to retreive them from the project's "Audio" folder. If you have the "Per Project Audio Folder" option enabled then it'll be in the sub folder Sonar created for the project (simply called "Audio"). NOTE: The default setting is to use a "Global" audio folder which lumps ALL recorded audio from all projects into one folder. That SUCKS (and you'll see ONE of the reasons why  momentarily) so any newdudes/dudettes reading this change that IMMEDIATELY. They may have even made PPF the default now but if not they really should. It's a confusing and semi obscure setting/concept for beginners and I do not see ANY positive benefit of having a "Global" audio folder. Maybe it made things easier to delete when hard drive space was limited and expensive.
 
Anyway... if you lost an audio file look in that folder. They are just raw waves (or whatever format you chose Sonar to record to). They (IIRC) are named after the track they were recorded into with take numbers. HOWEVER I find the easiest way to retrieve those files (because there can be ALOT of them) is to sort the folder by "Date Created". If I remember the general date when I recorded the missing part I just scroll down and peruse the file names for that date(s). You can even listen to the files to make sure they are the one you want. Then just import the wav back into your project (hopefully into its original track and at it's original position... which is a good reason to ALWAYS have "Snap" enabled to at least something like 1/4 beat before positioning the "Now Time" before recording ANYTHING. It makes it MUCH easier to sync up the waves to the original project in these cases... if you don't have snap on then you have to totally line it up by ear which is time consuming).
 
Here's the thing though... I'm not entirely sure what Sonar's protocall is for saving audio files. I think under ideal conditions it is this...
 
1) You record a bunch of stuff. Those recordings are stored on your hardrive but "temporarily"
 
2) If you hit Save or Save As then those files get put into and remain in the project (or global) audio folder even after you close the program.
 
3) If you close the project WITHOUT saving then the recordings do not get saved anywhere on the system. So the "temporary" files that were created get deleted automagically when you close Sonar.
 
Now let's say you DELETE a track or clip in the project AFTER reopening the project (AFTER doing a Save or Save As in your previous session). Since the audio files were created AND saved and already present in the audio folder I think the action of deleting that Track/Clip in the new session (and afterward saving) the audio file(s) will remain in the Audio folder. They are just no longer referenced by the project but still exist on your hard drive (in the audio folder). So (if that's true and I'm pretty sure it is) then you can restore those files manually as I described above.
 
Keep in mind though that if you then did a Save As of that project to a new location (like an external drive) with the "Copy Audio With Project" (or whatever it is called) then THAT version of the project (the one where you deleted the tracks and didn't restore the audio somehow) would NOT drag the deleted audio from the original project's audio folder with it because the new project does not "reference" those audio clips anymore.
 
 
Alright... so I totally veered off topic there (kind of) but the way Sonar (and most audio programs) handle audio files was a TOTAL mind twister for me as a n00b so maybe my blatherings about this stuff will help others muscle through a little better and be able to recover from these types of seemingly "worst case scenarios".
 
Also I haven't been up here for a while. Been working hard on some toonage stuff.
 
Hope everyone is good and well.
 
Cheers.