Cannot Install after unsuccessful removal

[caldia]

We had a rebuild of a site and can not get Xmap to install. We have tried to uninstall and manually removed all the files and menu items in the menu table (Joomla 2.5.4)

Each time we try to install we get
Another menu item with the same parent has this alias
Error building Admin Menus
JInstaller: :Install: File already exists /var/www/vhosts/ourwebsite.org/httpdocs/administrator/language/en-GB/en-GB.plg_xmap_com_mtree.ini

But then it says
Installing package was successful.

But there is no menu item in the J! admin.

We tried the fix of manually uploading all the folders form tne install and the same thing---just cannot get Xmap installed???