500 Internal Server error when visiting Backlogs

[liyamahendra]

I'm using Backlogs from feature/redmine3 branch with Redmine 3.2.0.stable on heroku. I've my redmine up and working fine. However, when I go to "Backlogs" it results into "500 Internal Server Error". Checking heroku logs I see the following line:

2016-02-20T14:02:13.138953+00:00 heroku[router]: at=info method=GET path="/rb/server_variables.js" host=myapp.herokuapp.com request_id=079840fd-4b93-4de8-817e-d5781a292b9d fwd="106.51.225.161" dyno=web.1 connect=0ms service=19ms status=500 bytes=924

My setup details are as below:

Environment:
Redline version: 3.2.0.stable
Ruby version: 2.2.4-p230 (2015-12-16) [x86_64-linux]
Rails version: 4.2.5
Environment: production
Database adapter: PostgreSQL
SCM:
Git: 1.9.1
Filesystem
Redmine plugins:
redmine_backlogs: v1.0.6
redmine_s3: 0.0.3

Can anybody suggest a fix for this error?

Thanks!