Not able to use Click bouton to set activity

Hello everyone,
I need a help with that case:
I want to set an activity in excell. However, once i try to reference where the activity has take place , i get an error message

" Indicate in Excel Failed. Error: Cannot attach to document ‘C:User… document.xlsx’. Make sure it is already open in Excel.

Excel appears to be busy. Please check that you are not editing a value and that no dialog windows are opened.

Moreover, i don’t have any of the problems indicated in the error message

I just want to set the activity in the space named: File name

Thank you for any help or advice,