Hi,
I have an excel workbook which is protected. When I upload it into the Document Library and try to open the excel file there, it works - Excel is asking for the password. However, when I enter the password, the file is only opened in a read only view and nobody could edit the cells and that's not the idea. Furthermore, when I upload the same file without a protection, all cells could be edited normally. 
Could you help me, how could I solve this problem? Thank you very much!