Found a workaround!, the issue is because there is no value in the $base variable of mod_mj_markupchooser.php
I think the error raises because the $base variable is assigned to $MobileJoomla->config['desktop_url'] but there is no desktop_url variable in config.php configuration file.
<?php
defined( '_JEXEC' ) or die( 'Restricted access' );
$MobileJoomla_Settings=array(
'version'=>'0.9.2',
'useragent'=>2,
'domains'=>0,
'pcpage'=>'',
'templatewidth'=>800,
'jpegquality'=>90,
'xhtmltemplate'=>'mobile_pda',
'xhtmlhomepage'=>'',
'xhtmlgzip'=>0,
'xhtmldomain'=>'pda.',
'xhtmlredirect'=>0,
'waptemplate'=>'mobile_wap',
'waphomepage'=>'',
'wapgzip'=>0,
'wapdomain'=>'wap.',
'wapredirect'=>0,
'imodetemplate'=>'mobile_imode',
'imodehomepage'=>'',
'imodegzip'=>0,
'imodedomain'=>'imode.',
'imoderedirect'=>0,
'iphonetemplate'=>'mobile_iphone',
'iphonehomepage'=>'',
'iphonegzip'=>1,
'iphonedomain'=>'iphone.',
'iphoneredirect'=>0,
'tmpl_xhtml_header1'=>'mj_pda_header',
'tmpl_xhtml_header2'=>'mj_pda_header2',
'tmpl_xhtml_pathway'=>1,
'tmpl_xhtml_pathwayhome'=>0,
'tmpl_xhtml_middle1'=>'mj_pda_middle',
'tmpl_xhtml_middle2'=>'mj_pda_middle2',
'tmpl_xhtml_componenthome'=>1,
'tmpl_xhtml_footer1'=>'mj_pda_footer',
'tmpl_xhtml_footer2'=>'mj_pda_footer2',
'tmpl_xhtml_jfooter'=>1,
'tmpl_xhtml_simplehead'=>0,
'tmpl_xhtml_allowextedit'=>0,
'tmpl_xhtml_removetags'=>1,
'tmpl_xhtml_removescripts'=>0,
'tmpl_xhtml_img'=>2,
'tmpl_xhtml_entitydecode'=>0,
'tmpl_xhtml_embedcss'=>0,
'tmpl_xhtml_contenttype'=>3,
'tmpl_xhtml_xmlhead'=>0,
'tmpl_xhtml_doctype'=>2,
'tmpl_xhtml_xmlns'=>1,
'tmpl_wap_header'=>'mj_wap_header',
'tmpl_wap_pathway'=>1,
'tmpl_wap_pathwayhome'=>0,
'tmpl_wap_middle'=>'mj_wap_middle',
'tmpl_wap_componenthome'=>1,
'tmpl_wap_footer'=>'mj_wap_footer',
'tmpl_wap_cards'=>'mj_wap_cards',
'tmpl_wap_jfooter'=>1,
'tmpl_wap_removetags'=>1,
'tmpl_wap_img'=>1,
'tmpl_wap_entitydecode'=>1,
'tmpl_wap_doctype'=>1,
'tmpl_imode_header1'=>'mj_imode_header',
'tmpl_imode_header2'=>'mj_imode_header2',
'tmpl_imode_pathway'=>1,
'tmpl_imode_pathwayhome'=>0,
'tmpl_imode_middle1'=>'mj_imode_middle',
'tmpl_imode_middle2'=>'mj_imode_middle2',
'tmpl_imode_componenthome'=>1,
'tmpl_imode_footer1'=>'mj_imode_footer',
'tmpl_imode_footer2'=>'mj_imode_footer2',
'tmpl_imode_jfooter'=>1,
'tmpl_imode_removetags'=>1,
'tmpl_imode_img'=>2,
'tmpl_imode_entitydecode'=>0,
'tmpl_imode_doctype'=>1,
'tmpl_iphone_header1'=>'mj_iphone_header',
'tmpl_iphone_header2'=>'mj_pda_header ',
'tmpl_iphone_pathway'=>0,
'tmpl_iphone_pathwayhome'=>0,
'tmpl_iphone_middle1'=>'mj_iphone_middle',
'tmpl_iphone_middle2'=>'mj_iphone_middle2',
'tmpl_iphone_componenthome'=>0,
'tmpl_iphone_footer1'=>'mj_iphone_footer',
'tmpl_iphone_footer2'=>'mj_iphone_footer2',
'tmpl_iphone_jfooter'=>0,
'tmpl_iphone_img'=>2,
'xhtml_buffer_width'=>20,
'wml_buffer_width'=>10,
'iphone_buffer_width'=>40,
'chtml_buffer_width'=>20,
'tmpl_iphone_removetags'=>0
);
?>
