Opera blocked by OSX 10.8.5 Currently I am on OSX 10.8.5, I don't want to upgrade for multiple reasons. 
Yesterday out of the blue, the OS stops running after rebooting the machine and tells me I cannot use Opera anymore unless I update to OSX 10.9

I started by downloading older versions of Opera (Currently on 42, downloaded each version back to 37) and in every download get the same install OS X 10.9 message. 

Any idea anybody? Thanks for the support. 

Note: Upgrading to a later version of macOS is not an option in this case - please do not suggest this as a solution.
You could install 10.8.5 clean on an external drive and just install the opera version you hope to use and test in a clean os. If that fails, you’ll know the program opera had a timer of sorts and can pursue disabling or modifying opera. 

If it works, you can then migrate all your settings / apps / data (except opera) to the new os and test. Then restore that image over the broken internal install. 

Splitting the troubleshooting up will save you time isolating and testing without risking your current setup that you wish to remain without an upgrade for reasons.