Excel in read only

[PTCOS]

I have Office 2016 and everytime i make a change in my excel document the document says it is a read only and that i must save it with a different name. Just loaded office on it a few weeks ago and it was fine until about 7 days ago.

[#2]

Where is the document stored exactly?

[#3]

its is stored in my desktop/ home screen

[#4]

Can you save, add and remove other files from that location? (try with e.g. a text file)