Hello! I use one Audio Data folder for all my projects. Recently I've found that it is flooded with empty wav files with names like this:
"Rec (2116).wav" or with similar names with project name ahead of it. Their size is 4096 bytes and they have no sound. What could it be?

4096 is probably the block size. Any file generated by any program will take up that much space regardless of what's in it. If you cut a sliver of silence off of a clip, it may have been saved as a file through one of several possible processes.
 
I highly recommend you use per-project audio files. A common folder for audio data dates back to the days when hard disk storage was expensive, but remains a part of SONAR for legacy compatibility.

Are they all exactly the same size? How many of them, dozens or hundreds? How does their creation time match with the files that actually belong to a project? Can you make any conclusions based on that?
I strongly recommend you start using per project audo folders. It makes back copying so much more organized, and can be a life saver in many problem situations.

Ok, I've tested it more. Every time I create new project from Sonar's Quick Start window, it makes 12 wav files in Audio Data folder, doesn't matter if Audio per Project is on. They disappear when I close Sonar. So they have accumulated after crashes.
Single Audio Data folder is much better for me, because I rarely exchange Sonar projects. I very often create projects just for testing, or practicing, and i hate to choose name and folder every time, knowing, that i will not even save this file. There can't be easier to backup it, i just have folder on other disk where i copy all new files from Audio Data. It is much more convenient than to have it in the huge project folders tree. And i have it on separate disk than project files.

When I'm just messing around to find something coming up w/ a name is hard and inconvenient ).  And of course if you have synth rack demo or something saved, you have to make a synth rack demo 2 (listening, Cakewalk?).  But still, I've collected a bunch of audio files in the Audio data folder, but I always use project folders for real songs.

Adq
Ok, I've tested it more. Every time I create new project from Sonar's Quick Start window, it makes 12 wav files in Audio Data folder, doesn't matter if Audio per Project is on. They disappear when I close Sonar. So they have accumulated after crashes.
Single Audio Data folder is much better for me, because I rarely exchange Sonar projects. I very often create projects just for testing, or practicing, and i hate to choose name and folder every time, knowing, that i will not even save this file. There can't be easier to backup it, i just have folder on other disk where i copy all new files from Audio Data. It is much more convenient than to have it in the huge project folders tree. And i have it on separate disk than project files.

I never share projects either but I've lost count of the times I've needed to verify the existence/size/date etc of an audio file within a project. and this is super easy when using PPF's because they all live in one folder.
 
Imagine how daunting this would be with every single audio file in one humongous folder?
 
You are also increasing the size/time of your backups. If you backup regularly (which you are doing yes?) then you're copying all these "empty" files with every backup.
 
Do yourself a favour and switch to Per Project Folders

I can't agree. One single Audio Data folder is much better.
And yes, it could be even more better without this empty files.
Do you have this files too?
I'm sure I can simply delete them. But I am just curious why Sonar creates them?

There's a config setting that creates these (Always Open All Devices?  not sure off the top of my head) and if your template has some input monitored tracks on.  Sorry I can't be more specific right now!
 
I'd worry about SONAR crashing lots more than a few kilobytes of disk space being eaten to be honest...

KPerry
There's a config setting that creates these

Thank you!
It's important "Allow Arm Changes During Playback/Record" option. When it is on, and "Only For Inputs In Project" option is off, this files are always created. It is pre-allocate files for recoding. It creates 1 stereo and 2 mono files for each audio input enabled, their size is regulating by "Record Pre-allocate File" option.
There is an issue in preferences menu organizing. "Allow Arm Changes During Playback/Record" and "Only For Inputs In Project" options are in project menu, but they are global options.

KPerry
I'd worry about SONAR crashing lots more than a few kilobytes of disk space being eaten to be honest...

Sonar will always crash because of plug-ins, BitBridge, and so on. So I don't worry about it too much. In this case disk space doesn't matter, number of files does.

That's the setting - glad you could work it out!