Clicking 'Use individual for un-named matches below' returns "Error updating encounter"

What Wildbook are you working in?
Flukebook

What is the entire URL out of the browser, exactly where the error occurred?
https://www.flukebook.org/iaResults.jsp?taskId=6d7d61df-35f1-4e61-b7d0-e7ce7f25aede&projectIdPrefix=BRDRight-%23%23%23%23

Can you describe what the issue is you’re experiencing?
My student and I were attempting to do matching, from the list of encounters obtained by clicking on the relevant project (Balearic Risso’s Photo ID right side) - we click on ‘Match results’ and then ‘view’, and have no problem ‘confirming no match’ for new individuals but after that when we try and match them by clicking ‘Use individual for un-named matches below’ we get a message replacing that button saying ‘Error updating encounter’ and no changes are reflected in the project encounter list.

Can you provide steps on how to reproduce what you’re experiencing?
Click on ‘My projects’ > select ‘Balearic Risso’s PhotoID Right side’ > select unmatched encounter and click ‘Match results’ > click ‘view’ > confirm no match for new individual > wait for screen to reload > locate matching unnamed encounters and select check box(es) > click ‘Use individual for un-named matches below’ → get ‘Error updating encounter’

This happens whether we use my or my student’s account.

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