We've released Synapse 1.4.1 as a small but important bugfix to 1.4.0.
This fixes a regression which crept in with our newly implemented "erase redacted data after N days" feature where some APIs would fail when hitting erased redactions - anyone on Synapse 1.4.0 will want to upgrade asap.
The changelog since 1.4.0 follows:
Synapse 1.4.1 (2019-10-18)
No changes since 1.4.1rc1.