You can also add the pde nature to your project in which you placed the product configuration file, if you want to be able to start your product via a right-click on the product and by selecting Run-as → Eclipse Application.
Note The Package Explorer view may have a filter set for .*resources. You can modify this filter via the view menu as depicted in the following screenshot.
For this purpose remove the filter in the Package Explorer view for files starting with . (dot) and modify the .project file to the following.
<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
<name>com.example.e4.rcp.todo.product</name>
<comment></comment>
<projects>
</projects>
<buildSpec>
<buildCommand>
<name>org.eclipse.pde.ManifestBuilder</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>org.eclipse.pde.SchemaBuilder</name>
<arguments>
</arguments>
</buildCommand>
</buildSpec>
<natures>
<nature>org.eclipse.pde.PluginNature</nature>
</natures>
</projectDescription>