# What should I do when I find circularity among duplicates?

Occasionally, when trying to vote to close some question, you get the error message: This closure would result in the 'duplicate of' navigation only leading in a circle.

AFAIK the system should prevent from occurrences of loops between duplicates, but they still happen for various reasons.

What should I do, when I find something like this? Should I flag some of the questions in the cycle when I see this? Should I post on meta that there is a problem like this?

Likely the fastest way to resolve this would be to flag one of the questions for the ♦-mods, preferably stating where the circularity is if it is more complicated, and possibly also how you think it should be resolved. Since the ♦-mods can re-open/close questions with a single mouse click, the circularity can be removed rather quickly, even if it means re-opening a question only to close it as a duplicate of a different question.

I see little reason to start a separate meta thread about these individual cases.

• I disagree, There should be a tool someone clicks to check. Each question may be a duplicate of one question, this means it is probably a column in the schema (what I'd do), you need only check the duplicates until you hit "0" (or null, value for not a duplicate) or get back to where you are. Duplicates are usually only 2 deep, should be easy. – Alec Teal Mar 31 '14 at 22:03
• @AlecTeal: From my understanding the system does a quick check (I think of some fixed depth). This takes care of the vast majority of cases (since most closure cycles really aren't more that three or four long). The case presented above happened (I believe) because two questions were somewhat simultaneously being closed as duplicates of each other. Once one was closed as such, I think that future users couldn't choose it as a duplicate of the other, however already existing votes were retained. (cont...) – user642796 Apr 1 '14 at 7:01
• (...inued) There might be a possible feature request here so that whenever a question is closed as a duplicate, then all existing votes to close the "original" version of that question as a duplicate of the closed are altered/invalidated. But this might be too intensive (and possible too invasive) for a problem that rarely occurs. – user642796 Apr 1 '14 at 7:04
• BTW this feature request at meta.SO to prevent circular duplicate links is marked as (status-completed). – Martin Sleziak Apr 1 '14 at 8:48