EPEL causing RPMDB error on all RHEL6 machines

Hello all! We're having a fun issue with all of our RHEL6 machines.
Running a search with EPEL enabled produces the following error: "Error:
no such table: packagetags." This error is present on all RHEL6 machines
even after resyncing the EPEL repository and clearing the yum cache with
'yum clean all.' Disabling EPEL causes the error to go away, verifying
that it is an issue with that particular repository. This also only breaks
search - retrieving and updating packages from EPEL still works as
intended.

We also have RHEL7 content views that do not have this issue. Deleting our
RHEL6 content views to remove/re-add the repo is unfortunately not an
option. We're currently on Katello 3.0. If anyone has run in to this or
has any advice, your help would be greatly appreciated. Thanks for reading!