This is on a VMWare 6.5 Workstation running Vista Ultimate 32-bit with 2GB RAM on a 45GB drive with 8 GB free.
Steps to reproduce:
1) Install DevForce for Silverlight RC1
2) Go through the Four Simple Steps Walkthrough
3a) Open up a solution based solely on SL3 CTP 9, or,
3b) Close and re-open Visual Studio 2008, and open up a solution based on Silverlight 3
CTP 9 (Alexandria, SL3 and .Net RIA Services) -- either a walkthrough or a
self-developed solution
4) Press F5 or Play button, and the following message box appears once building has started:
Re-boot, open VS2008, and load the same or any other SL3 project - same result.