Stream is inaccessible due to 'Invalid order of events has been detected in read index for the event stream'

Our EventStore cluster has been stable for quite a while. However, since recently we are unable to access a stream. The following error is logged each time the stream is accessed:

[PID:11435:026 2018.10.08 07:18:50.181 ERROR StorageReaderWorker ] Error during processing ReadStreamEventsForward request.

System.Exception: Invalid order of events has been detected in read index for the event stream ‘SNIP-c6c032b7-1d9c-66a9-1f4b-c14cfcc26432’. The event 6 at position 1948977563 goes after the event 1 at posit

at EventStore.Core.Services.Storage.StorageReaderWorker.CheckEventsOrder (EventStore.Core.Messages.ClientMessage+ReadStreamEventsForward msg, EventStore.Core.Services.Storage.ReaderIndex.IndexReadStreamResuff67fb68564269afea7f7d0c2d2519>:0

at EventStore.Core.Services.Storage.StorageReaderWorker.ReadStreamEventsForward (EventStore.Core.Messages.ClientMessage+ReadStreamEventsForward msg) [0x000fa] in <1dff67fb68564269afea7f7d0c2d2519>:0

Our first bet would be to rebuild the read index but the index directory is empty. A listing of the db folder is attached. Our cluster consists of two nodes, both have version 4.1.1-hotfix1-1 installed.

Is there any way to recover access to the stream?

Db.PNG