An unexpected error is preventing me from launching my sprint. Screenshot attached.

[Fon Ngu Sr]

The following error message is preventing me from starting my sprint. I don't know what to do to solve this problem.

Here is the error message, but I have also attached a screenshot.

Start sprint

Issues CPFM2-7, CPFM2-6, CPFM2-5, CPFM2-4 and 2 others do not have a value for the 'Estimate' field. Values entered after the start of the sprint will be treated as scope change.

[Trudy Claspill]

That message is not an error, it is a warning. You can still start the sprint by clicking the Start button at the bottom of the dialog.

In your Board Settings you have specified an Estimation Statistic. This message is telling you that for the specified issue you have not set a value for that field. 

You should complete estimating your issues before you start the sprint, but the application will not force you to do that.

[Nic Brough -Adaptavist-]

There is an accept button on the screen you are seeing, but it is a better practice to estimate all your issues, rather than include unrefined ones in your sprints.