Try complete disabling CCleaner and do a test.
If it doesn't work, uninstall Opera removing all data, download Opera 35.0.2066.82 from here and install it.
If both do no work, then i'm out of ideas.
Thank you for your continous help.
I have said that I 'was' using CCleaner since this issue happened. I forgot to mention that this program has been uninstalled before I have created this thread. Apologies.
It might been caused by CCleaner, but possibly you can't fix this problem, if you used it at least once.
But fourtunatelly I think this time I solved this issue for good. If anyone have same problem; I managed to fix it by installing Opera 37 developer release. So far, the extensions have saved over night, so I think it fixed all together.
It may not be profile corrupt, but something sitting more deep in my system that causes this to happen only on Opera 35.
Thanks again for you help.