'Job done' but Burai still shows 'stop calculation'

Dear Dr. Satomichi Nishihara,

I am new user of Burai, and I confuse that in the log file it shows 'job done' but on the interface of Burai, there is still a control button: 'stop calculation'. If I click on this 'stop calculation', it shows a warning that I am sure to stop or not.

So my question is: is it safe to close projects (exit Burai software) when 'Job done' is shown in log file?

Actually, I hope when there is a message 'job done' in log file, then there is no 'stop calculation' button on the interface.

Thanks for your useful software.