We've suddenly started having the same issue this morning with a Kanban board, and it is not the result of any configuration changes. The board was fine yesterday evening and then broken at the start of the working day today, and the Audit Log has no activity in the past 7 days.
We experienced the same issue just by this morning. Several projects in the company were affected and we couldn't access the active sprints. But we decided to done a quick fix by re-created scrum/kanban board for each of the affected projects and use the new one as the default board instead (we also deleted the old error board). I know this might be bothering and may take some time, yet still better than cannot accessing the active sprints at all.
Hope it helps!
It's worth checking the audit logs to see what the issue might be.
I've seen this issue before when a filter is not valid - for example:
If all the boards aren't working though - rather than just one - the audit log is more likely to have the details. You can also try performing a re-index of your instance.
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events