I recently reinstalled Windows 10 on my laptop, as well as Vegas Movie Studio 15 Platinum. I've been using this software on this laptop for a year now with no issues, only reinstalled the OS for OCD reason. Start fresh every year or so. I can't render anything now, always getting the message "An error has occurred while creating the media file [name of file] The reason for the error could not be determined." I've done a ton of searching online, reading forums here and elsewhere, watching videos and I can't get this resolved. A completely fresh install of the software with all the default settings and folder locations, opening it up for the first time and seeing the "Welcome" project that comes with the software and trying to render it with standard settings as MP4 throws that error as soon as I hit the button to start rendering. I've tried with many of my own projects as well with the same result, I just wanted to point out that the project that comes with the software to help you learn it even fails immediately after a fresh install.
Any help would be much appreciated. I can give detailed specs of my laptop if needed. It's not a powerhouse by any means but it has ran this program and rendered a ton of project videos over the last year with no issues. I've tried with GPU rendering off and there are no NAS folder locations used. Those are common fixes I've seen for this error.