During selective backup/restore, the oplog applier replays upgradeDowngradeViewlessTimeseries on a timeseries collection that was not restored. The guard that is supposed to skip this op checks isView(), which can be true due to the view being recreated by oplog replay even though the backing buckets collection is missing (since the buckets collection was created before the backup checkpoint timestamp and therefore not included in the data files). This causes a tassert.