Error when trying to preview PDF documents with TeXlipse

Question

I'm using TeXlipse (LaTeX plugin for eclipse) and I want to preview my LaTeX document.

I have configured yap in the viewer settings.
When I push the preview button I get an error in the console:

Error: Project output file format not set in project: thesis.

I don't understand the message, because I set the output file and it works, because when I save, the auto save compile function produces the correct output pdf

Here is my .texlipse file

#TeXlipse project settings
#Thu Jun 21 20:51:48 CEST 2012
markTmpDer=true
builderNum=2
outputDir=
makeIndSty=
bibrefDir=
outputFormat=pdf
tempDir=tmp/
mainTexFile=template.tex
outputFile=main.pdf
langSpell=de
markDer=true
srcDir=

and my .project file

<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
    <name>thesis</name>
    <comment></comment>
    <projects>
    </projects>
    <buildSpec>
        <buildCommand>
            <name>net.sourceforge.texlipse.builder.TexlipseBuilder</name>
            <arguments>
            </arguments>
        </buildCommand>
    </buildSpec>
    <natures>
        <nature>net.sourceforge.texlipse.builder.TexlipseNature</nature>
    </natures>
    <linkedResources>
        <link>
            <name>.tex</name>
            <type>1</type>
            <location>C:/Program Files (x86)/MiKTeX 2.9/tex/latex/tools/.tex</location>
        </link>
        <link>
            <name>mybib.bib</name>
            <type>1</type>
            <location>C:/Users/thunder/AppData/Roaming/MiKTeX/2.9/bibtex/bib/ijqc/mybib.bib</location>
        </link>
    </linkedResources>
</projectDescription>

Answer 1

YAP is a DVI viewer, not a PDF viewer. Therefore it cannot open your PDF file, as the error message informs you: