Im an Opera user, and the quests were working fine 2 months ago. I returned to Play again after this time has passed and quests are not working anymore, tried several games and this error keep reocurring.
Have you checked to see if your version of Opera has enabled the Flash Player? Some of the newer builds of browsers for Chrome and Firefox have been patched to disable flash by default so it's possible for your version of the browser this may be the cause.
If you can share what OS and Browser version you have I can try and do some testing. If you are not sure which version, you can use https://www.whatismybrowser.com/ to find out. We only need the OS version, browser name, browser version and the Flash Player version from the linked page.
You also mentioned quests not working and an error. If you can share the game, quests and a screen capture or the text of the error with us, we can also look into these further.
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