diOne
Firstly, Welcome to the Chandoo.org Forums
This can occur for a number of reasons
Is the file or directory Read Only ?
Is the file a Network directory ?
Is the file corrupt?
Has the file been downloaded from a READ ONLY source, ie: The Internet or email?
I download and save files to my Desktop
But in Excel I have setup my Desktop as a Trusted Location
Open any file even a new blank file
Goto File, Options, Trust Centre, Trust Centre Settings
Click on Trusted Locations
Check that they make sense
here is mine
Also check Trusted Documents
Is the directory where your file in Read Only ?
Uncheck if it is