'As far as being sarcastic and rude, obviously it isn't your hours of painstaking work seeming to disappear, leading to hours of unanticipated detective work'
 
What makes you think that nobody here hasn't experienced data loss with an application? I am willing to bet everybody here has done so . Anyway you have had quite a few pointers  here I suggest drawing a line and let us try and help you debug. I wrote a few suggestions myself any feedback will help us help you. It is noticable that 4 of us had made similar points about opening the backups. Keep calm and get down to the bottom of this I suggest, all of us would like to see you get your work back.
 
Thanks...

In my experience with opening an old project with the project being setup for equipment that is no longer on the system is Sonar will warn me that I have buses or gear that is not what is listed in the project. Often its because I have different MIDI ports and a different audio interface. It will also alert me to missing plugins. 
 
If I than save the file so that it overwrites the old file (which I don't do. I aways use save as.), than it should reflect any changes I did to the new setup.
 
I have never had to resort to safe mode or had any problem opening any project. 
 
 

A great example of why to never, never, ever to use SAVE.
 
I ONLY use SAVE AS to a new name about every 5 minutes. Years of habit.
 
wish the CW managers would fix the auto save function
 
AND GIVE ME A SAVE AS BUTTON

Look, there aren't a bunch of threads in this forum with folks having these problems, so like it or not, until something surfaces otherwise, this is likely due to circumstances local to your particular environment.  
 
Please do not take the above statement as a 'works here' comment, as that is not at all the point I am trying to make.  
 
Problems that affect a bunch of folks are reported by a bunch of folks, so that this has not happened for this set of reported problems is an indication that it is probably something we can figure out, as it is most likely a local issue.
 
I promise you I will give best effort at helping you get this stuff figured out, as long as we can work at it cooperatively.  I can also assure you that the folks who had responded earlier also routinely bend over backwards for folks, to try to solve issues that can be solved.  (It's after midnight here, and I have spent the last hour digging through things on the web looking for ways to help you)
 
Here is the link for the driver/firmware updates page for you:
 
http://www.lynxstudio.com/support_downloads_results.asp?prod=1&type=0
 
Few questions for you:
 
1.  Do you have the latest X3 maintenance applied?  (X3e)
2.  You indicated some 8.5.3 projects open in X3, which is very helpful to know.  Can you try to detail differences between the ones that do open, and the ones that are now messed up?  That might also help narrow things down.
3.  Are you running with ASIO as your driver mode in X3?  (Lynx had prior issues when not running ASIO, if I recall correctly from some time ago).
 
Hang in there,
 
Bob Bone
 
 

jm24
A great example of why to never, never, ever to use SAVE.
 
I ONLY use SAVE AS to a new name about every 5 minutes. Years of habit.
 
wish the CW managers would fix the auto save function
 
AND GIVE ME A SAVE AS BUTTON

Auto Save is a "save as" function that never overwrites your original file. Why would you want it "fixed" to overwrite a file? I think that would be asking for trouble...

jm24
A great example of why to never, never, ever to use SAVE.
 
I ONLY use SAVE AS to a new name about every 5 minutes. Years of habit.
 
wish the CW managers would fix the auto save function
 
AND GIVE ME A SAVE AS BUTTON

Anderton
Auto Save is a "save as" function that never overwrites your original file. Why would you want it "fixed" to overwrite a file? I think that would be asking for trouble...

 
I really don't understand how this is related to the OP's issue.
 
I use "save as" all the time as I don't use autosave. It's no big deal I like to give projects different titles as I progress. I am disciplined about when I save. Other people use autosave. Pick your poison they both work (and when you are backing up to a hard drive you are laughing).
 
Yup it would be nice to have a save as button but one extra click ain't gonna hurt you.

I use auto save.  But I want it to add the date and time, or a sequential letter or number, before the file extension. Adding AUTO SAVE at the beginning of the file name results in bounced wave files also having AUTO SAVE at the beginning of the file name. Screws-up sorting in a file manager.
 
 Rarely do any versions get saved here because I reset the clock with each save as.   And the versions function adds the date time as part of the extension and the files do not appear in the file open browser.
 
I want to be able to set file name defaults for the auto save function.
 
My comment about this is that the OP prolly does not have a bunch of previous copies of the files to be able to trouble shoot the issue.
 
I am sad for him. Not admonishing him.
 
 

The OP has lost his work and we hope to help him recover it. This is work from 8.x (wasn't there an autosave button with 8.x?). Anyway he says he has backups (please read earlier in thread about his backups). From what he is saying I (we?) don't think the projects could be corrupted unless he has managed to save over his external backups somehow (seems unlikely). Even then it could be recoverable as it looks like it could be an issue with his environment. This thread has nothing to do with save as. Sorry.
 
Here is a thread that is relevant to your topic:
http://forum.cakewalk.com/Feature-Request-39Save39-button-on-control-bar-m2227201.aspx
 

"What makes you think that nobody here hasn't experienced data loss with an application?"
 
What makes you think that I think that nobody here hasn't experienced data loss with an application? Please don't put words into my mouth.
 
"I am willing to bet everybody here has done so."
 
So the platform is inherently buggy? I've experienced data loss before, just not this way. And I chalked it up to my previous computer's having to max out its processing power. It would sometimes simply crash. But I'd open a previous version of the project and get back to work.
 
I'm older than the average person here, and software architechure is an area of ignorance for me. And I keep getting the impression that Cakewalk is mainly focused on more and more sophisticated methods of data manipulation at the expense of having a stable recording/ mixing platform that gets the basic thigs right before moving on to the more elaborate, esoteric functions.
 
Case in point: the mute buttons on the stereo busses don't work.
 
"They work for for me!"
 
Oh, will you shut the @%$# up?
 
The reason they work for you is because, like 99% of the people here, you are either a) not using external inserts in your master bus or b) not using stereo busses for sub-groups.
 
So if I have a guitars bus, a background vocals bus and a drums bus, I can't solo the busses to do any fine tuning. If I delete the external insert on the master bus, I can solo the stereo busses but that doesn't do me any good because whatever I'm hearing will be radically changed when I re-insert the hardware compressor. And a FET III works better for me than any software compressor I've tried.

You have taken me totally out of context and bent it so you can vent at somebody in an aggressive manner. Never mind I will take it on the chin.

I see where this thread is going, sadly you would rather vent at people trying to help then get to the bottom of your issue it seems, been here before sadly and have become wise to it. People have already asked a few questions to help you and you haven't provided feedback. Good luck I hope you find a solution (and calm down!).