.htaccess deny from all

This syntax has changed with the newer Apache HTTPd server, please see upgrade to apache 2.4 doc for full details.

2.2 configuration syntax was

Order deny,allow
Deny from all

2.4 configuration now is

Require all denied

Thus, this 2.2 syntax

order deny,allow
deny from all
allow from 127.0.0.1

Would ne now written

Require local

Deny from all 

is an .htaccess command(the actual content of that file you are trying to view). Not a denial of being able to edit the file. Just reopen the .htaccess file in the text viewer of choice and make the alterations as you so desire, save it, then reupload it to your folder of choice.

Though I think inadvertently you are blocking even yourself from viewing said application once uploaded.

I would do something like:

order deny,allow
deny from all
allow from 127.0.0.1

which will deny everyone but the IP in the allow from line, which you would change the IP to match your IP which you can obtain from http://www.whatismyip.com/ or similar site.