@roquez

I have now nuked Opera completely after I have saved all bookmarks and thumbnail pictures before.
Then I reinstalled the newest version. When it worked I manually recovered all settings and imported the bookmarks.
It seems as if Opera update doesn't work properly when you use Opera a certain time and automatic update has updated it many, many times.
I hope updates in the future will not cause so much anger again.

In the past I had similar problems after a Windows update for Intel/ Nvidia (I don't know which of both was the trouble maker). But it is much more nasty when the system is damaged, not only the browser.

PS:

I found the bookmark files including the thumbnail pictures manually and imported it to the flash drive version of Opera.
It works...

Opera still doesn't work in the installed version so I have to use IE.

But I have put the portable version on flash drive. This one works!!!
Though I cannot import the bookmarks from installed Opera because I cannot export them in two seconds between start and crash. That's really annoying.

@Ceedee

As long as Opera crashes immediately (within 2 seconds) I can do NOTHING at all.
I think the automatic update to 52.0.2871.37 destroyed my Opera.

Remember: My Opera version still is 51.0.2830.55

PS:

Meanwhile in "About Opera" Version 52.0.2871.37 is shown. I have to click very quick to reach "About opera" before Opera crashes.

PPS:

It didn't work to install Opera newly with the offline-installer over the old installation. The problem persists.
52.0.2871.37 seems to be Riesenscheißdreck!!!

Since today opera crashes right after starting it every time I try. I guess it has updated itself in the first ten minutes of using it.
I write this on IE.
Opera Version is 51.0.2830.55

VPN worked for some days then when I wanted to choose Singapore, it stopped working forever. It is no more connecting, and the list with the places like Singapore or others is empty.

Hallo,
in den letzten Wochen habe ich bereits mehrmals einen Alarm der AVG-Verhaltenserkennung bekommen, nachdem das Opera-Update irgendwie aktiv war. AVG beschwerte sich über irgendeinen Installer. Es wäre schön, wenn Opera-Updates nicht diese irritierenden Meldungen verursachen würde, zumal das nur bei Opera passiert. Vorsichtshalber lasse ich das Programm die scheinbare Bedrohung stets entfernen, ob real oder nicht. Das Entfernen hat jedenfalls auch keine erkennbaren Probleme verursacht.
Vielleicht könnten die Opera-Programmierer ja bei Gelegenheit für Abhilfe sorgen.
VG,
Teuropa