Fatal Error on administrator section

Hello,
Need your help, please. It appears there is any issue with my administrator section - I get the following Fatal Error:
Fatal error: Call to a member function getInt() on a non-object in /public_html/administrator/components/com_postinstall/models/messages.php on line 37

Thanks

Hello,

Thank you for contacting us.
I guess that this issue appeared after updating your Joomla to 3.2 version. First of all, please update your Joomla to the latest 3.2.1 version and check if the issue still occurs, if yes then please check this forum topic:

forum.joomla.org/viewtopic.php?f=710&t=825422&start=30

As you can read there, these steps should help you to solve your issue:

1. Uninstall anything that is Akeeba Related - plugins, modules, components - all of them.
2. Uninstall FOF Library (Extensions-> Manage-> Filter by FOF), but NOT the one with id 105. The one to uninstall is actually with ID 10000+ something.
3. Re-upload the following folder from the Joomla! package: libraries/fof into your site.

Hope this will be helpful for you as well.

Regards,
Marcin