When I open an assebly it's fine, but when i opened an assembly in an assembly it's telling me that :
The internal ID of document **** does not match the internal ID saved with the referencing document.Select YES to accept this document anyway. Select NO to browse for a replacement model.

That file exists, and if I click yes it's ok.. and the next time I open that whole assembly it asks me again. If I click "No" I click on that assembly and it doesn't accept it. It tells me again that it couldn't find it.

I'm a student and i can't resolve it.