I am running on Windows 8.1 x64. It appears that all of the issues (audio and drag/drop MIDI) seem to be related. I ran an earlier version of RC, and the same problems happened; the issues are also now happening with my Sonar X3 as well.
I did perform a "SFC /SCANNOW" and found some corruption on the windows system image, so I ran the DISM utility ("Dism /Online /Cleanup-Image /RestoreHealth") to repair the corruption. The last time I had corruption like that, it was related to faulty Windows update patches. Whether or not the image corruption is responsible for the problems I am having now, I do not know.
The audio problems are a result of the JackAudio server failing to connect to the named pipe that gets created to link the audio between the JackAudio server and the ASIO drivers of the audio applications. As is the case with drag & drop, named pipes require that all involved applications are running with a compatible Windows "Mandatory Integrity Level" in order for system messages to propagate between applications.
For some reason on my system, RapidComposer and Sonar are now running with an integrity level that requires the JackAudio server to be run with elevated privileges in order to interoperate with these two applications.
I noticed that if I ran the RC installer and left the "Run RapidComposer Now" checkbox checked before exiting the installer, RC would run with a suitable integrity level (TrustedInstaller): drag & drop of MIDI files from Windows explorer and the JackAudio ASIO driver work fine for that session.
I checked the RC installation folder and for some reason it, along with all of its contents, was owned by the Adminstrator user instead of my own user. Ditto for Sonar. After fixing this (by changing the owner of the files and folders), I am now able to run RC and Sonar with suitable integrity. However, RC and Sonar still do not run with suitable integrity from the shortcuts pinned to the start menu.


