Hikashop Components submenu missing & cart offline

Bought and installed the Hikashop Essential.tar file - seemed to install fine, but had this appear above the "successful installation" view:
Notice: Trying to get property of non-object in /hermes/bosoraweb020/b234/nf.textilesamano/public_html/administrator/components/com_hikashop/helpers/update.php on line 446

Notice: Trying to get property of non-object in /hermes/bosoraweb020/b234/nf.textilesamano/public_html/administrator/components/com_hikashop/helpers/update.php on line 458

Notice: Trying to get property of non-object in /hermes/bosoraweb020/b234/nf.textilesamano/public_html/administrator/components/com_hikashop/helpers/update.php on line 461

Notice: Trying to get property of non-object in /hermes/bosoraweb020/b234/nf.textilesamano/public_html/administrator/components/com_hikashop/helpers/update.php on line 464

Notice: Trying to get property of non-object in /hermes/bosoraweb020/b234/nf.textilesamano/public_html/administrator/components/com_hikashop/helpers/update.php on line 467

Notice: Trying to get property of non-object in /hermes/bosoraweb020/b234/nf.textilesamano/public_html/administrator/components/com_hikashop/helpers/update.php on line 468
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Now the Hikashop submenu under Components is missing, and the "add to cart" button is missing in all my products. I am able to access Hikashop after installing the update, but I cannot access it if I navigate away to any other joomla section. Joomla is up-to-date, using 2.5.4. I tried installing the starter version again - that did not fix it, nor did installing the essential version after. Please help!

www.textilesamano.com

This first appears when installing the component:
JTableMenu:_getNode Failed -
Error building Admin Menus

Installing component was successful.

Please wait... HikaShop will now automatically install the Plugins and the Modules.

This screen is then followed by the one I listed below.

Thanks, any help is appreciated!

~Tamara

Hi,

Try to change the position of the menu in the Joomla settings.
For the add to cart button, just try to re-set the option in the main options of hikashop, and in the module display options.

Could you give us the code corresponding to the line 446 of the indicated file ?