Audio Driver Failed!

[djones]

I'm having some problems with one of my current projects.
In which it won't load my Virus anymore.
I get this error, 'the audio driver failed to start or is not installed etc....'.

But if I start other projects I have no problems at all.

But what can I try to get it working again in this project?
I've tried removing the Virus from this project, saving it under a different name and then reopening it, to then add the Virus into my project.
That worked fine.
But when I saved it again, including the Virus and reopened the newly renamed project, then again it wouldn't load.