Web interface not running/cann't run installer

[Aranel]

Hi all.
We have an installed LanSweeper on W2008 Enterprise SP2.
Suddenly, web interface has stopped working. LanSweeper service, configuration program starts, there are no errors in logs. But in web-console we get "HTTP Error 503".
I cannot run installer too, because:

Anybody can help?

[Hemoco]

Please download the latest version of the installer from http://www.lansweeper.com/download.aspx