Unable to login after Ghost upgrade 0.6.4 -> 0.7.5

Issue Summary

After performing an upgrade of Ghost via git on the stable branch, I was unable to login via /ghost/signin I get the following error message on the server during an attempt at login.

ERROR: Client Authentication Failed
 Client credentials were not provided
 For information on how to fix this, please read http://api.ghost.org/docs/client-authentication

ERROR: Access denied.

This is the request headers and information of the failed login

Request URL:http://www.mydomain.com/ghost/api/v0.1/authentication/token
Request Method:POST
Status Code:401 Unauthorized
Cache-Control:no-cache, private, no-store, must-revalidate, max-stale=0, post-check=0, pre-check=0
Connection:keep-alive
Content-Length:73
Content-Type:application/json; charset=utf-8
Date:Sun, 31 Jan 2016 17:04:05 GMT
ETag:W/"49-6DP22JQ8bA10Qm37R/5VFQ"
Server:nginx
Vary:Accept-Encoding
X-Powered-By:Express
Accept:application/json, text/javascript, */*; q=0.01
Accept-Encoding:gzip, deflate
Accept-Language:en-US,en;q=0.8
Cache-Control:no-cache
Connection:keep-alive
Content-Length:120
Content-Type:application/x-www-form-urlencoded
Host:www.mydomain.com
Origin:http://www.mydomain.com
Pragma:no-cache
Referer:http://www.mydomain.com/ghost/signin/
User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.97 Safari/537.36
X-Requested-With:XMLHttpRequest
grant_type:password
username:***redacted***
password:***redacted***
client_id:ghost-admin

Steps to Reproduce

1. Upgrade Ghost through git
2. npm install --production; npm start --production
3. Login to Ghost blog, and receive a Access Denied error.

Technical details:

• Ghost Version: stable (latest commit: 3dd772768b9d91bbb8126b5859396b85d8410f18)
• Client OS: Mac OS X 10.11.2
• Server OS: Ubuntu 12.04
• Node Version: 0.10.40
• Browser: Firefox Version 44.0, Safari Version 9.0.2 (11601.3.9) and Chrome Version 48.0.2564.97 (64-bit)
• Database: SQLite

[jieyanhuang]

@kevinansfield, thanks for the assistance on this issue. For anyone that tries to upgrade through git, do remember to run grunt init and grunt prod before you restart your ghost instance. The problem I was facing was due to an old copy of the JS file being served after the upgrade.

[jankuca]

Thank for the tips. Worked for me as well but I had to clear core/client/bower_components before running grunt init because of the following error:

bower                  ECONFLICT Unable to find suitable version for mocha
 Use --force to continue.

Aborted due to warnings.