Steps to reproduce:
Create domain and subnet, assign the subnet to the domain
Hosts > New Host
Select Organization and location
Switch to Network tab
Select domain

Expected behavior:
Subnet list provides available subnets for the domain

Current behavior:
No subnets are available. PGError received from controller but not shown

PGError:

Warning!
PGError: ERROR: column reference "id" is ambiguous LINE 1: SELECT id FROM "subnets" INNER JOIN "subnet_domains" ON "sub... ^ : SELECT id FROM "subnets" INNER JOIN "subnet_domains" ON "subnets"."id" = "subnet_domains"."subnet_id" WHERE "subnets"."id" IN (1) AND "subnet_domains"."domain_id" = 1 ORDER BY vlanid

If you feel this is an error with Foreman itself, please open a new issue with Foreman ticketing system, You would probably need to attach the Full trace and relevant log entries.
ActiveRecord::StatementInvalid
PGError: ERROR: column reference "id" is ambiguous LINE 1: SELECT id FROM "subnets" INNER JOIN "subnet_domains" ON "sub... ^ : SELECT id FROM "subnets" INNER JOIN "subnet_domains" ON "subnets"."id" = "subnet_domains"."subnet_id" WHERE "subnets"."id" IN (1) AND "subnet_domains"."domain_id" = 1 ORDER BY vlanid
app/helpers/hosts_and_hostgroups_helper.rb:31:in `domain_subnets'
app/views/common/_domain.html.erb:2:in `block in _app_views_common__domain_html_erb___3366442248415189655_70262450388580'
app/views/common/_domain.html.erb:1:in `_app_views_common__domain_html_erb___3366442248415189655_70262450388580'
app/controllers/concerns/foreman/controller/host_details.rb:49:in `block in assign_parameter'
app/models/taxonomy.rb:59:in `block (2 levels) in as_taxonomy'
app/models/concerns/foreman/thread_session.rb:148:in `as_location'
app/models/taxonomy.rb:58:in `block in as_taxonomy'
app/models/concerns/foreman/thread_session.rb:113:in `as_org'
app/models/taxonomy.rb:57:in `as_taxonomy'
app/controllers/concerns/foreman/controller/host_details.rb:46:in `assign_parameter'
app/controllers/concerns/foreman/controller/host_details.rb:22:in `block (2 levels) in domain_selected'
app/controllers/concerns/foreman/controller/host_details.rb:21:in `domain_selected'
app/models/concerns/foreman/thread_session.rb:33:in `clear_thread'
lib/middleware/catch_json_parse_errors.rb:9:in `call' 

Installed on centos 6.5 from nightly at 5.12. with options

--capsule-dhcp=true \
    --capsule-dhcp-range='192.168.115.10 192.168.115.254' \
    --capsule-dhcp-gateway=192.168.115.1 \
    --capsule-dhcp-interface=eth0 \
    --capsule-dns=true \
    --capsule-dns-reverse='115.168.192.in-addr.arpa' \
    --capsule-dns-zone='v2' \
    --capsule-tftp=true"