Encountered this bug during first run of the 3.0 beta. In the 2.2 version this worked.
SharpDevelop Version : 3.0.0.2970
.NET Version : 2.0.50727.1434
OS Version : Microsoft Windows NT 6.0.6001 Service Pack 1
Current culture : Dutch (Netherlands) (nl-NL)
Current UI language : en-US
Running under WOW6432, processor architecture: AMD64
Working Set Memory : 133860kb
GC Heap Memory : 25172kb
Exception thrown:
Debugger.DebuggerException: Process is not in collection
at Debugger.NDebugger.GetProcess(ICorDebugProcess corProcess)
at Debugger.ManagedCallbackSwitch.GetProcessCallbackInterface(ICorDebugProcess pProcess)
at Debugger.ManagedCallbackProxy.<>c__DisplayClass49.<DebuggerError>b__48()
at Debugger.Interop.MTA2STA.<>c__DisplayClass3.<EnqueueCall>b__0()
at Debugger.Interop.MTA2STA.PerformCall()
at Debugger.Interop.MTA2STA.PerformAllCalls()
at Debugger.Interop.MTA2STA.Call(MethodInvoker callDelegate, Boolean hasReturnValue)
at Debugger.Interop.MTA2STA.Call[T](MethodInvokerWithReturnValue`1 callDelegate)
at Debugger.Process.CreateProcess(NDebugger debugger, String filename, String workingDirectory, String arguments)
at Debugger.NDebugger.Start(String filename, String workingDirectory, String arguments)
at ICSharpCode.SharpDevelop.Services.WindowsDebugger.Start(ProcessStartInfo processStartInfo)
at ICSharpCode.SharpDevelop.Project.CompilableProject.Start(String program, Boolean withDebugging)
at ICSharpCode.SharpDevelop.Project.CompilableProject.Start(Boolean withDebugging)
at ICSharpCode.SharpDevelop.Project.Commands.Execute.<>c__DisplayClass1.<Run>b__0(Object , EventArgs )
at ICSharpCode.SharpDevelop.Project.Commands.AbstractBuildMenuCommand.CallbackMethod(BuildResults results)