Will this remove all the existing url that i have created in the store?will the upgradation will be easy?

Hello,
Now it installs but giving an error and my store is being offline,
Fatal error: Call to undefined method JoomSEF::_getMenuItemInfo() in /home/melodin/public_html/components/com_sef/sef_ext/com_virtuemart.php on line 180

Please help,

Hello,
My order number is 6301 ,i thought the last suffix should be 2.x ,the site i am going to use it at melodi.no ,can you please send me the 3.x version,
I also sent an email to support too,
Thank you ,

Hello,
I just bough ext_joomsef2_virtuemart for my joomla site melodi.no ,this is running ARTIO JoomSEF v3.2.2 so i bought the 2.x plugn and tried to nstall via SEF plugin installer,but whats that,
It gave a error while installing and store is down,i want a remedy asap ,i didnt see any support there ,
Please help