It seems that my tags, configured in Settings, are being ignored.

how do you mean? if you are referring to blacklisting content you need to put each word you want blacklisted on it's own line

eg this blacklists all posts tagged with dog, all posts with fat, and all posts with glasses

dog
fat
glasses

or if you want to block specific circumstance
this would block all posts where dog, fat, and glasses are tags on the posts in question.

dog fat glasses

That is how I have it. It has been working fine for years. In fact, I haven't changed it in some time however, it suddenly stopped recognizing any of the keywords.

Is it possible the engine parsing the keywords throws an exception that is being unhandled and so it stops the filter but still displays based upon the keywords entered into the search?

somefoxsomewhere said:
That is how I have it. It has been working fine for years. In fact, I haven't changed it in some time however, it suddenly stopped recognizing any of the keywords.

Is it possible the engine parsing the keywords throws an exception that is being unhandled and so it stops the filter but still displays based upon the keywords entered into the search?

I know that sometimes when a heavy strain is put on the site there are temporary lapses in some site features, it's possible that the problem could fix it self, I could also be completely wrong on the issue that you're experiencing. If it persists you might want to ask an admin to peak at your blacklist

Double check that your browser is still processing JavaScript. The search itself is handled by our server, but the blacklist is processed locally on your end using some simple JavaScript.

Blacklist processing is client-side and the blacklist is stored in a cookie (as well as on the server in your account data), so server load generally shouldn't interfere.

@somefoxsomewhere: Blacklist doesn't interact directly with the tags in your search. What happens is, all of the results from the current page of your search are returned (including blacklisted ones). Then any items which match a rule in your blacklist are hidden.

One basic test I'd suggest is to logout, clear your cookies for e621, and then log back in, then see if blacklisting is working.

I had Javascript disabled. Creating an exception fixed it. Thank you to all who replied!