I following installation and configuration instructions at [[plugins/teximg/]]

But I get

    [[!teximg Error: missing tex code]]

for code

    [[!teximg $$\sin (x)$$]]

On server I do have `texlive`, `dvips`, `convert` installed ready. My configuration looks like

        # teximg_dvipng => 1,   # use dvipng                                                                                                                
        teximg_dvipng => 0, # use dvips and convert                                                                                                         
        # LaTeX prefix for teximg plugin                                                                                                                    
        teximg_prefix => '\\documentclass{article}                                                                                                          
        \\usepackage{amsmath}                                                                                                                               
        \\usepackage{amsfonts}                                                                                                                              
        \\usepackage{amssymb}                                                                                                                               
        \\pagestyle{empty}                                                                                                                                  
        \\begin{document}                                                                                                                                   
        ',
        # LaTeX postfix for teximg plugin                                                                                                                   
        teximg_postfix => '\\end{document}',

Any ideas why it's not working?