@leocg To be honest, it doesnt matter for me, if it happened 1 time or 10 times. It never happened for 10 years since now, nobody have same issue, so I already decided to reinstall complete PC. I dont want to spent more time with analysing and trying. I need to work on my computer without problems.
Thank you for your time and support.

@leocg Sorry for late reply, what you mean how long? I tried it 2 times and in both cases it happened.

@leocg A did exactly this:

• deactivated synchronisation
• uninstall opera
• deleted all directories in users (local, Roaming...all of them)
• switched off/on PC
• install opera
• opera started for the first time, I signed to my account, synchronisation was still off
• stored 2 passwords, 4 list with pages opened
• switched off/on PC
• started opera and again everything was deleted

@leocg I tried with synchro OFF and same result. Tried it twice and also one more time with syncho ON. Still same issue

@leocg OK, I will do, let you know tomorrow or at Saturday. Thanks

@leocg Yes, on the new profile. For this new profile, that I created, I enabled synchronisation. So after signing on, some data are synchronised back. But why it always disconnecting me.

@leocg So its not working Today after start of PC Opera is again at the start. Again all accounts disconnected, all passwords disappeared. Do you please have another idea? Last my idea is to reinstall PC completely, but thats my nightmare

@leocg Thank you, it looks like it is working. A renamed it and create brand new account and after one restart it stayed as before, Hope it will stay forever. One more time thank you