Excel calculation formulaes quits before finishing the job

When doing a calculation (shift F9), the process stops before all cells are calculated. This happens since about a month. My students, who have installed seotools for excel as well, report the same problem.

Explicitely calculating the cell by simply giving an 'enter' on the formulae does calculate the cell, so the formulae itself is right.

So my quesiton is why the calculation of the whole sheet stops, before it is finished?

Thanks!

What version of SeoTools are you using?

You need to debug your sheet step by step and see where is stops.

Thanks for your respons.
My seotoolsforexcel version is: 5.1.3
The strange thing is, that it doesn't happen every time.
How can I debug the sheet step by step? I can see there are ways to debug VBA macro's and single formulaes, but not a sheet of formulaes...
Thanks again!

Did you set the sheet to manual calculations?

Definitely! Always...

And I calculate the sheet by shift-F9

Are updates installed automatically? In that case: could it be that the newest version of seotoolsforexcel doesn't have this problem anymore? Because I tried several times to reproduce the error, and it goes well every time, now.

No updates are not installed automatically.