Indexer restarts

I have a 10 node Couchbase cluster (6 x data nodes, 2 x index and 2 x query) that I’m using for development testing using 4.5.1 (2844).

Today I started noticing issues with the indexer, where it would restart every few minutes with the following error:

Service ‘indexer’ exited with status 1. Restarting. Messages: C:/Jenkins/workspace/watson-windows/couchbase/goproj/src/ +0x5c3
[FDB INFO] Forestdb blockcache size 1048576 initialized in 0 us

[FDB INFO] Forestdb opened database file c:\Program Files\Couchbase\Server\var\lib\couchbase\data@2i\MetadataStore
[goport] 2016/12/23 08:38:12 c:/Program Files/Couchbase/Server/bin/indexer.exe terminated: exit status 2

This happens even when the cluster is sitting there idling doing nothing - no indexes being created or data being loaded or queried. I also restarted all the nodes one by one, but this still occurs.

Any suggestions on what could cause caused this?