When you download a file from the portal and open it with office tools, you can not edit it because it is in protected view (it is read only)
This is a standard function for office 2010 and thereafter in case you download files from untrusted sites (internet). It has to do with protection issues from macro commands.
One solutions is to download it to your disk and then to open it from your hard disk (as Tolga Dince stated at the e-mail)
Other solutions can be found here:
http://www.msoutlook.info/question/884
https://support.office.com/en-au/article/What-is-Protected-View-d6f09ac7-e6b9-4495-8e43-2bbcdbcb6653
Regards
This is a standard function for office 2010 and thereafter in case you download files from untrusted sites (internet). It has to do with protection issues from macro commands.
One solutions is to download it to your disk and then to open it from your hard disk (as Tolga Dince stated at the e-mail)
Other solutions can be found here:
http://www.msoutlook.info/question/884
https://support.office.com/en-au/article/What-is-Protected-View-d6f09ac7-e6b9-4495-8e43-2bbcdbcb6653
Regards