You have probably updated your browser - Firefox, chrome etc, and probably in the old version you had downloaded (perhaps automatically) a switched off adblocker that has reactivated. Or maybe you have some antivirus software that detects the check servers do to detect adblockers, and disable the response - this would look to the server as an adblocker.
Unless you can locate the adblocker, which might be tricky if your computer skills are a bit er, undeveloped, you are a bit stuck. In Chrome, for example, they're called extensions, and accessed via a little blobby icon top right. Firefox calls them add-ons. Safari has extensions again - so maybe that will let you do a little hunting. The other thing of course, is just ignore the messages and put up with the message. I suppose the question is do you see adverts? This forum doesn't have very many to be honest. On safari I get a small banner at the top. In Chrome, it's missing. The ads help the forum, so just go on the hunt for extensions or add-ons in the top menus and disable them.
You have been a member here for a long time, so your computer skills cannot be as bad as you say - forgive me, but you seem to be lacking nosiness - as in looking at menus you dont normally use and having a fiddle. Have courage my friend - or as my wife does, ask the 10 yr old grandson when all else fails. RR won't get cross with you - the adblocker message is automated and designed to be annoying, that's all.