The NPE is caused by the project not being a laszlo project.
You get this typically when you created a new Java project and add a
laszlo file to it.
Im not sure if this is the best way but the way I fixed it was the
following:
Created a new Laszlo project.
Edit the .project file in a text editor
Copied the natures and linkedResources
<nature>org.eclipse.laszlo.rct.builder.RCTNature</nature>
<linkedResources>
<link>
<name>lzp</name>
<type>2</type>
<location>o:/eclipse/eclipse/plugins/org.eclipse.laszlo.rct.lzx.core_0.2.0/resources/lfc</location>
</link>
<link>
<name>lzp-components</name>
<type>2</type>
<location>O:/Program Files/Apache Group/tomcat
5.5/webapps/openlaszlo/lps/components</location>
</link>
</linkedResources>
and added them to my other .project in the appropiate sections of the
file. (note do not replace the
<nature>org.eclipse.jdt.core.javanature</nature> just add the element
below it like
<natures>
<nature>org.eclipse.jdt.core.javanature</nature>
<nature>org.eclipse.laszlo.rct.builder.RCTNature</nature>
</natures>