I can't drag MIDI or WAV files from the file system to Sonar. Now this is not something I do frequently, so this may have stopped working some time ago, or perhaps there is a setting I need to change?
 
Windows 8.1, Sonar X3e... anyone have suggestions for a fix?
 
Thanks!

Can you drag the same files from one folder to another folder? 
Can you drag the same files into another application? Is the response different for 32 bit vs 64 bit programs?
Are you running Sonar as administrator, or under an administrator account? Were the files you are dragging created and saved in the same account you are using to run Sonar now?
 
Permission issues are common in Win 8. Your program typically runs under the same permissions as the account it was launched from, but it may have been set to always run as administrator. Typically files saved by one user are not fully available to another user or the programs running under the different account.

Can you use the import process to get them in?
 

Please, check if your wave file has a symbol or an accent in the name; I had this problem sometime ago and I found it was the culprit...

I have the same in X3. I can import the files with no problem, but when I try to drag and drop wav files into Sonar i get the red round circle that states not allowed.

Looks like slartabartfast already threw out this possibility, but, whenever I've had this issue, it's because I've been running Sonar as an administrator.

Running Sonar as Administrator does this for me (which some plugins seem to require).

Or don't run Sonar as Administrator, depends on how you are set up, try both to see which could be at fault. I've heard reports of either way.

The only reason to run Sonar as Administrator is to register certain plugins, once it is done it is done. There are some legacy plugins that might need permission, and the better way (rather than run as admin) is to allow elevated permissions on their registry settings.
 
Cheers..

This happened to me recently as well. I've been able to drag and drop before, but suddenly I couldn't. I was able to get the file in via "import file" in the menu. 

skitch_84
This happened to me recently as well. I've been able to drag and drop before, but suddenly I couldn't. I was able to get the file in via "import file" in the menu. 

 I had some files that would appear to drag and drop but the file would not show up in the track. My assumption is that it was the files are these were new files in Sonar's media browser and it needs to scan them first.