I don't want to say the PR has fixed this issue, more like it allows the refresh to finish if a lan wasn't saved for whatever reason and thus couldn't load the ID for future use.
We still need to investigate why a lan in the collection wasn't saved but there is a log warning with the lan uid_ems and the switch ID when this happens which can help us further diagnose.
New commit detected on ManageIQ/manageiq/master:
Author: Adam Grare <email@example.com>
AuthorDate: Tue Feb 5 15:08:18 2019 -0500
Commit: Adam Grare <firstname.lastname@example.org>
CommitDate: Tue Feb 5 15:08:18 2019 -0500
Fix save_inventory error if lan can't be found
When loading IDs of newly saved lans skip any that can't be found by
app/models/ems_refresh/save_inventory_infra.rb | 8 +
1 file changed, 8 insertions(+)