I'm having this problem on Windows 8 32-bit with LMMS 0.4.15. It's installed on an external drive, but that can't be the problem. There are tons of other programs installed to the same parent directory on there that run with no problem. I have never been able to successfully run it.
Is the Win 8 OS, on your Hard drive, or running from your external Hard drive?
Could you give us more info about where the OS is installed.
However:
If you have a main HD with the Win 8 OS, and an external HD, without the OS installed on it, try installing it on your main Hard drive, where the WIn 8 OS is located, and let the Lmms installer, install Lmms in the default Win 8 program file path.
If you haven't done this, and instead, chose a custom file path for Lmms to install, there is a possibility that some necessary files or folders, may not have installed in the correct path or place.
And the Lmms program, can't seem to find them in order to run the Lmms program.
Or possibly, these files may have not installed at all.
I hate when that happens.
If the OS is on the external HD and so is the OS, and you're running the OS from the external HD, then let the Lmms installer install Lmms into the default folder paths. That way, all of the folders, will be installed in the correct place.
Also, I see on the net that some WIn 8 users are having problems, installing 3rd party software. Wow!
Even Win 8 64 bit users as well.
I hope I could help here. If not, please post more info.
So we could try to help you further.
I'll be back.