I did something wrong with my joomla based page. When I go to /administration/ I have only message:
There are important post-installation messages that require your attention. To view those messages please click on the Review Messages button below. You can review the messages at any time by clicking on the Components, Post-installation messages menu item of your site's Administrator section. This information area won't appear when you have hidden all messages.
And no more any buttons and menus. How to get back administration environment?