Eclispe Helios Plug-in Development Target Platform Template Base-RCP broken?

Question

I'm trying to create a standard osgi bundle under Eclipse Helios.

To do so, I've configured my Target Platform like this:

1. Window -> Preferences -> Plug-in Development -> Target Platform -> Add
2. After I choose Template and Base RCP (Binary Only)
3. I changed the name and clicked Finish.

When I launch the platform using the Overview of my bundle, I've got this error printed in the console :

!SESSION 2010-07-16 15:44:37.987 -----------------------------------------------
eclipse.buildId=unknown
java.version=1.6.0_18
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=fr_FR
Command-line arguments:  -dev file:C:/Documents and Settings/E364866/Desktop/calendar/antonio osgi tutorial/.metadata/.plugins/org.eclipse.pde.core/OSGI DynaResume/dev.properties -os win32 -ws win32 -arch x86 -consoleLog -console

!ENTRY org.eclipse.ui 4 4 2010-07-16 15:44:44.659
!MESSAGE Unable to load UI activator

!ENTRY org.eclipse.ui 4 4 2010-07-16 15:44:44.659
!MESSAGE Unable to load UI activator
!STACK 0

I've managed to make the platform run by deselecting the org.eclipse.ui plug-in in the platform configuration window, but I don't understand why this plug-in is selected by default.

Answer 1

Quoting the comments in org.eclipse.ui.internal.WorkbenchPlugin:

// The UI plugin needs to be initialized so that it can install the callback in PrefUtil,
// which needs to be done as early as possible, before the workbench
// accesses any API preferences.

org.eclipse.ui plugin needs to load before your plug-in. You may fix this problem by giving it a start level less than your bundle's start level (which is probably set at default 4).