This doesn't address the error you are receiving but may help in debugging the problem. The method I use to debug windows services may work for you.
1. Add this code to your source code where you want to start debugging:
// pulls up window to attach to debugger when in debug mode.
#if DEBUG
System.Diagnostics.Debugger.Launch();
#endif
2. Recompile all your assembliesin debug mode.
3. Set your breakpoints.
4. If running from a different locationcopy the debug exe and dlls to that location.
5. Start your app. Whenthe appgets to the code above a window is displayed asking you to select a debugger. Select the running Visual Studio program that has your solution open. This attaches the process to your project.
Hope this helps.
Diane