Start of a new sprint
Start of a sprint with un-estimated issues
You have a sprint formed and you want to start it.
There are un-estimated issues in this sprint.
If you click on the Start Sprint button, a pop-up window will appear with the notification "Unable to start sprint with non-estimated issues".
To start a sprint, you need to put an estimate in those tasks that do not have it.
After that, the sprint can be started.