@Magdalene @BugSir009 @Mhzayer @migel thank you very much!
My home Mx.6000 suddenly stopped working last week (Facebook logged out and can't log in again, can't login to my account on the Internet provider etc). I didn't install any new extensions, didn't browse any dangerous sites, just usual home Internet environment. Nevertheless on the phone (Facebook) and my office PC with .6000 all sites are ok. I cleared all user data and removed Maxthon. I tried to install the latest beta and you see what happend. It doesn't work. I see the problem on my side and I can't figure out what happened. All other things on my home PC are ok. No crashes, no unusual activities, no virus detections. Except the Maxthon.
I am really sorry I have disturbed you.