They may not go bad. They could be malformed from the beginning. They could get corrupted due to disk failure. I have read about a known problem with RIFF files mixing mono and stereo waves in Win 7. Don't know how to perform a postmortem on a failed bundle. Bundle failures are catastrophic. I believe it is possible to break out the project and the waves by hand using a hex editor but I have not had the pleasure.

mudgel
People have also had cwp files become corrupted but it's not the fault of the file type that has caused the problem. Neither is the file type the problem with bundle files. The fact is that any type of computer data can become corrupted.

For sure! I've had way more issues with corrupt WRK/CWPs than BUN/CWBs. Though I haven't really used them since the X series started, it's possible the trouble with BUNs may start with a bad project file.
 
The issue may also be related to creating the BUN in one version and opening it in another, especially a pre-X file in X.
 
If I were afraid of them I would take the time to wrap a project in a Windows ZIP folder.

Whenever I've used cwb files I've always expanded them again to make sure that everything works fine before relying n them. I do the same with zip or other compressed file data. After creating an archive always test it to make sure that none of the files are corrupted.

Over the years I've only used Bundles for long-distance collaborations.  It's certainly the slickest way to have other people receive, open and work with a project.  Otherwise, archiving project folders which contain the .cwp version files (however many there may be) and the sub-folder of audio data is tidy, and doesn't involve unpacking.  Simple. I don't want to deal with opening a bundle, saving it again and yadda yadda.

Randy B.

mudgel
Whenever I've used cwb files I've always expanded them again to make sure that everything works fine before relying n them. I do the same with zip or other compressed file data. After creating an archive always test it to make sure that none of the files are corrupted.

And here is the key to success with bun files (or any backup for that matter!)

""I tried an experiment. 
I made a test project with a audio file and a Midi drum track. Nothing else. No efxs or instruments. I saved it as a CWP per project folder and noted the file size.""
 
Hi Cactus Music, you wrote this and you are also the OP.
I stated that the bundle file  works very well as far as REDUCING THE SIZE, only on a project when you have made a lot of changes, and or recording and re-recordings.
Save As onto another folder still does not solve this.
For example, I have a song that I have been working on for 1 month now.
Right now, the Audio folder is 1.4 gig long.
Save As to another folder brings it down to 850 MGB.
Save as Bundle brings it down to 700 MBG. Then open the bundle file and save again as a cwp file, now brings it down to the same size, plus or minus a few bytes.
I have done this all the time and the bundle file is the only way to bring it down to the minimum size.
All I am saying is yes I save by using the cwp method. For sure. But I also save every song as a bundle file too.
That's it. Why not using 2 methods for peace of mind when it is available to you. Besides the fact that it get rid of the stuff that you no longer need.
dan

dan le
Besides the fact that it get rid of the stuff that you no longer need.
dan

I'm going to give this a try.

OK, but my experiment was to prove to myself that Bun files did not compress the audio. If they did the file which was just a 3 minute MP3 which was 4.3 MB  song I imported, and so then became 43 MB because Sonar up converts to 32 Bit wave. It would have shown a difference in file size if the buns compressed the audio right? 
Both the CWP and the CWB where identical in file size and only a few KB bigger than a 3 minute stereo wave file.In other words the CWP or CWB icon uses very little data, we all know midi is in the KB's not MB's. File size is all to do with our audio.  
 
So what your saying is a Bun file does some sort of cleaning of the audio folder? interesting. 
 
I always was under the impression that performing a "save as" of an open project only saved the active audio files and left behind any old takes and deleted edits. 

A bundle is a file created by appending a cwp with the audio referenced in the cwp. The only "compression" I am aware of is the where multiple regions are "flattened" into a single chunk of audio. This activity is why bundles cannot store audio snap data. I would guess the cwp is written out specially for the bundle which in addition to removing audio snap data may explain why it would decrease in size.

Hi Cactus Music:
Yes it does get rid of stuff that you already:
1. deleted or
2. apply trimming.
So on and so forth.
Like I said many times on different threads here, you have to take an old project and do the bun file thing, and see that the size of the bun file is smaller than the combined length of the audio folder (even after you save as in another folder). And only if you already did a whole bunch of editing, play over and over some tracks, etc...
That is why I am still using bun file, basically to bring down the size of the project.
Yes, hard drive is cheap nowaday, but if the unwanted tracks are still there in a cwp file, you never know when they are going to show up when you go back to the project and do some more editing.
I just want to be sure.  That's all. And I never understand why people have to feel so negatively about something like a bundle file.
It is a tool, a good one instead.
I charge my customers, so I don't want to make any mistake at all.
Now if you do music just for yourself, then you can do anything you want to.  I guess.
Cheers.
dan
ps: again if you create a brand new project, with no editing, then bundle or cwp file will be at the same size.