Emonhub error report

WARNING emonCMS send failure: wanted ‘ok’ but got ‘’

I posted some MQTT data a few days ago to node 9, later changing it to a different node number, but found that I couldn’t delete the node 9 entry, despite it no longer being used.
A check of MYSQL showed that there was no entry for node 9 in the table, so I suspected that it may be due to Redis.
Today, I flushed the redis cache, which did clear node 9, but upon doing so, all of my RF inputs stopped updating (MQTT inputs are OK).
Putting emonhub logging into DEBUG, I can see loads of messages;

2016-09-19 17:40:19,419 WARNING emonCMS couldn’t send to server, HTTPException
2016-09-19 17:40:19,421 WARNING emonCMS send failure: wanted ‘ok’ but got ‘’

It was working fine prior to flushing Redis.

Self hosted emoncms low-write 9.7.2 | 2016.07.04 built from scratch using @pb66 original emonhub.

@Paul - can you post the request that emonhub is sending?

Also if you set the “$display_errors” setting to true in emoncms/settings.php does that reveal anything? The "wanted ‘ok’ but got ‘’ " in emonhub.log may change to include an error.

Thanks Paul, I had managed to get things running again before seeing your post.

I assumed that this was something to do with Redis, so flushed redis again, this time from the cmd prompt, instead of from the Administration page, and rebooted. Still the same.

So, I changed ‘emoncms Low-write mode’ to false (disabling emoncms low write mode), and found that my feeds started updating again, and the errors reported in emonhub were no longer present, again supporting the notion that it was a redis issue.
So again flushed redis followed by re-enabling Low-write mode in settings.php and everything is back OK and working normally.