I have also now had a similar error that was previous reported where I cannot generate a preview.

I created a new theme (copy of the Vanilla theme) and uploaded it as a new plugin to the authoring tool. When I assigned that theme to the course in question and clicked 'Preview' I got this error on screen "Error generating preview, please contact Administrator".

Looking at the node server logs I get this:

server-0 (err): error: [07 Apr 2015 05:40:48 +00:00] undefined errno=34, code=ENOENT, path=/home/ec2-user/adapt_authorng/temp/548648aa051bb930029e4765/adapt_framework/src/theme/theme-gv-compliance
server-0 (err): error: [07 Apr 2015 05:42:22 +00:00] exec error: Error: Command failed:
server-0 (err): error: [07 Apr 2015 05:42:22 +00:00] Error: Command failed:

Then every subsequent time I try to save the theme and regenerate the preview I keep getting these two lines in the node server logs:

server-0 (err): error: [07 Apr 2015 05:42:22 +00:00] exec error: Error: Command failed:
server-0 (err): error: [07 Apr 2015 05:42:22 +00:00] Error: Command failed:

If I switch back to the Vanilla Theme and regenerate the preview it works. So because of that I thought it was my theme, however if I clean out the "adapt_authoring/temp" folder and let it all regenerate, I get the same errors on both my theme and the vanilla theme.

I am running the node server as root so I don't think it can be a permission thing??

Any ideas????