jomla site kurduktan sonra sobi2 eklentisini kurduğumda aşağısaki hatayı alıyorum sebebi ne olabilir

Installing base data ....
menu entries fixed ....

ERROR: The installation seemed to be ok but it is not possible to delete the installation file.

If you are using the Joomla! 1.5 FTP-Layer please switch it off or uninstall this component because SOBI2 is not able to work properly in this mode.

You can also try to manually remove the file: administrator/components/com_sobi2/install.sobi2.php