Can't add another member to the team, ShortListTooBigError

(marking as private as its for a private team, feel free to flip public)

I'm trying to add another member to a team, and get this: https://oops.canonical.com/?oopsid=OOPS-1ac1cc2d16e05116e67d676270dc6736
ShortListTooBigError: Hard limit of 1000 exceeded.

    Traceback (most recent call last):
  Module zope.publisher.publish, line 132, in publish
    result = publication.callObject(request, obj)
  Module lazr.restful.publisher, line 212, in callObject
    WebServicePublicationMixin, self).callObject(request, object)
  Module lp.services.webapp.publication, line 463, in callObject
    return mapply(ob, request.getPositionalArguments(), request)
  Module zope.publisher.publish, line 107, in mapply
    return debug_call(obj, args)
   - __traceback_info__: <security proxied lazr.restful._resource.EntryResource instance at 0x2aada6bbd590>
  Module zope.publisher.publish, line 113, in debug_call
    return obj(*args)
  Module lazr.restful._resource, line 925, in __call__
    result = self.do_POST()
  Module lazr.restful._resource, line 757, in do_POST
    return self.handleCustomPOST(operation_name)
  Module lazr.restful._resource, line 1397, in handleCustomPOST
    value = super(EntryResource, self).handleCustomPOST(operation_name)
  Module lazr.restful._resource, line 741, in handleCustomPOST
    return operation()
  Module lazr.restful._operation, line 81, in __call__
    self.context, providing=providedBy(self.context))
  Module lazr.lifecycle.snapshot, line 90, in __init__
    value, ISnapshotValueFactory, default=_marker)
  Module zope.component._api, line 102, in queryAdapter
    return adapter_hook(interface, object, name, default)
  Module zope.component.hooks, line 104, in adapter_hook
    return siteinfo.adapter_hook(interface, object, name, default)
  Module lp.services.webapp.snapshot, line 24, in snapshot_sql_result
    value, longest_expected=100, hardlimit=HARD_LIMIT_FOR_SNAPSHOT)
  Module lp.services.helpers, line 175, in shortlist
    'Hard limit of %d exceeded.' % hardlimit)
ShortListTooBigError: Hard limit of 1000 exceeded.