We suspect that your "File Permissions" is unwritable as you can see at Backend>Systems>System Information>File Permissions as shown http://prnt.sc/c9qy24. You have to contact your web server provider to change it to writetable. You have to change to writable for all option except "configuration.php". Please give it atry and see how it goes.
These links might come in handy. Please do take some time to read through some of these links: