I have created my own OG reference field with Entityreference to reference to a Group.
However, when I use Views to build a relationship via the og reference field, it shows the following error (see attachment):
SQLSTATE[42S22]: Column not found: 1054 Unknown column 'og_membership.field_budget_group_target_id' in 'on clause'
I have tried to use the core field_og_ref OG reference field to test and the error is still there.
I have tested both the lastest 7.x-2.x-dev and 7.x-2.0-rc2.