Hit the upgrade link and Plesk died

[nibb@]

I have plesk 7.5.4, i just hit the upgrade link to 8.0. Nothing happend, except php is down know, as well i the control panel is also down. Why do SW Soft put even allo the upgrade button to 8.0 if they know its not going to work? What do i to fix this know, so its just the same as before i hit the upgrade key. I mean with my normal plesk and all services running again. Its obvious plesk tried to upgrade and it failed, so how do i get back since it did not finish anything at all, so maybe it blocked the panel and other thing temporarily.