500 Error on every page after update. Undefined method 'builds_enabled=' in 'add_gon_variables'

Currently, Mattermast is the only part of my installation still working (assuming you still have a session). Any gitlab page gives a 500 error.

The exact error in production.log is:

NoMethodError (undefined method `builds_enabled=' for #<Project:0x000000099c0320>):
  app/controllers/application_controller.rb:194:in `add_gon_variables'

gitlab-rake db:migrate:status shows all migrations up.

I have run gitlab-ctl reconfigure and gitlab-ctl restart countless times with no change.

gitlab-rake cache:clear seems to have no effect, as well.

gitlab-rake gitlab:env:info gives:

System information
System:         Debian 8.2
Current User:   git
Using RVM:      no
Ruby Version:   2.1.7p400
Gem Version:    2.5.1
Bundler Version:1.10.6
Rake Version:   10.4.2
Sidekiq Version:4.0.1

GitLab information
Version:        8.3.1
Revision:       92e0722
Directory:      /opt/gitlab/embedded/service/gitlab-rails
DB Adapter:     postgresql
URL:            https://git.redacted.com
HTTP Clone URL: https://git.redacted.com/some-group/some-project.git
SSH Clone URL:  git@git.redacted.com:some-group/some-project.git
Using LDAP:     no
Using Omniauth: no

GitLab Shell
Version:        2.6.9
Repositories:   /var/opt/gitlab/git-data/repositories
Hooks:          /opt/gitlab/embedded/service/gitlab-shell/hooks/
Git:            /opt/gitlab/embedded/bin/git