Impossible to have stamped or combined

Hello everyone,
I have a problem I am under SW2020, I have this part and I would like to calculate the interior volume.
But it's impossible for me to do anything.
It is impossible for me to combine or do anything...
Does it come from my software or is something wrong...

Thank you in advance for your help

Assemblage_FILTRE_LXT.SLDPRT (2.3 MB)

All right... after a SW restart :face_with_raised_eyebrow: