For some reason latest Opera 49.0.2725.39 (PGO) for Windows does not give "allow Flash" button or dialogue on URL bar for number of web sites.
This is what I had to do. I went to settings and manually added the URL for each web site where I wish to allow Flash. Only that way I manage to get the Flash run on those web sites.
I hope this helps others to get this solved. Unfortunately there are number of great services still relying on Flash.