the cube file cannot be opened for writing
 

i've been working on the pivot table in Ms. Excel, the system produced
File.cub and File.oqy at last. As a result i can get the right answer and the
format i need, but there is a problem when i try to refresh data, i got an
error said The Cube file 'filepath\file.cub' cannot be opened for writing.
What should i deal with this? can anyone help?