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Your LimeSurvey version: 3.18.0+190923
Own server or LimeSurvey hosting: Dedicated CentOS WHM/Cpanel
Survey theme/template: fruity
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We have multiple closed access surveys in Version 3.18.0+190923 that are using tokens and set to prevent duplicate responses, however, I have noticed many cases where we have duplicate responses for a single token. 

We have an external application developed to import participant responses for the purposes of tracking completions and progress across multiple surveys. So these duplicate response records are causing some problems for us.

I have the following options configured:

Participant settings:
Enable token-based response persistence: On
Allow multiple responses or update responses with one token: Off

Notifications & Data:
Participant may save and resume later: on

Publication & access:
Set cookie to prevent repeated participation: on
 
Does anyone have ideas of why we are getting duplicate responses for some tokens? or how we might prevent duplicate responses?

Any help is greatly appreciated!

 
 

On the first glimpse, settings look correct.

However, before you continue with any bug hunting, you should update your installation to the latest LS3 and see if the problem perisist. I think it makes no sense to try to "fix an issue" in a version that is "pre-pandemic"...

3.18.0+190923

So this version hasn't received any update, bug fix, security patch since 23/09/2019, this is over 3,5 years now.

Thanks. Yes I realize our version of limesurvey is really old. We have been pretty gunshy to upgrade, because doing so in the past has caused some super problematic issues with surveys we are in field with. and since we are continually doing follow up surveys, there has never really been a great time to upgrade.

So I guess there is no reasonable recourse beyond "you need to upgrade"?

Well, I can't guarantee an update will solve your problem. But at the same time I don't think it makes any sense to deep dive into potential issues of such an old version of the software. In my (personal) opinion, this is a waste of time as the issue might not exist in the newest version anymore because it might have been solved in the last 3,5 years already.

I understand your concerns in terms of updates, but I never had any real problems with updates within the same major version. And based on that, there would never be a good time for an update. There is always some research running, there is always a good excuse somehow. So one day you need to take make the decision to update, even if it is not the perfect day.

If you have a SaaS solution, they will just inform you "On Day XXX there will be an update, expect some downtime." and you have little to no control over it.

And the smaller the jumps between versions, the lower the risk of something going really wrong in my opinion. I am also not always the first to update, but I try to stay fairly up to date. I follow the forum to see if an update causes problems for others and wait if there are real show stoppers. But for LS 3.x the updates are mostly minor things today, so I do not expect big issues caused by the current updates.

As I said, I don't think it makes much sense to try to find the cause of this issue (if it is a real LS issue at all) in a version this old.