So the same file that imported fine the first time is now giving you an error message? That seems odd.Did you only try the second time, or did you relaunch VisionLab repeatedly with the same results? Though if its also not importing any other media, something must have went screwy. I'd recommend a clean re-install, following these instructions:http://fxhome.com/forums/viewtopic.php?t=28295
As far as limitations of the demo, they are as follows:
Rendered footage will have a watermark.
You can't render out individual layers with alpha channels, due to the watermark system.
You can't import new presets.
That's pretty much it. The watermarks prevent you from using the demo footage in real projects, but other than that, everything is there and fully functional, without any time limit or anything.