Error: java.lang.IllegalStateException: Queue full

I'm testing a home-brewed Zigbee multi-sensor / router device for @iharyadi to report my findings on how well it works in routing Xiaomi devices.

To perform the testing, I needed to remove my XBee modules from my Hubitat's Zigbee network to ensure no devices pair / rejoin to one of them instead of @iharyadi's device.

In trying to rejoin my Sengled Classic ( E11-G13) bulbs that were previously routing through an XBee, I'm seeing a bunch of Queue full errors in the Logs output, like so:

2018-07-08 15:50:48.021: error java.lang.IllegalStateException: Queue full (refresh)
2018-07-08 15:50:22.877: error java.lang.IllegalStateException: Queue full (on)
2018-07-08 15:50:19.435: error java.lang.IllegalStateException: Queue full (off)
2018-07-08 15:50:16.852: error java.lang.IllegalStateException: Queue full (setLevel)
2018-07-08 15:48:43.770: error java.lang.IllegalStateException: Queue full (configure)
2018-07-08 15:48:43.691: warn configure...
2018-07-08 15:47:40.067: error java.lang.IllegalStateException: Queue full (refresh)
2018-07-08 15:47:34.171: error java.lang.IllegalStateException: Queue full (configure)
2018-07-08 15:47:34.096: warn configure...

It appears that the sensor/routing device isn't able to route my Sengled at present, but I've never seen this error before and was curious as to what it means. I'm guessing @mike.maxwell may know.

Firmware is 1.1.0.122, and for these Sengled bulbs, I'm using the Hubitat Generic Zigbee Bulb device driver.

EDIT: I just installed and assigned @iharyadi's current Hubitat device driver for his sensor, and after doing that, when I tried a manual configure command and then refresh, and those generated that same Queue full error in the logs. Very strange. I'm going to try restarting the hub.

EDIT #2: Rebooting the hub seems to have cleared out the Queue full errors. Now I am able to issue a configure command to all of my Sengled bulbs routing through @iharyadi's device, and they have come up as active and are working normally. So it turns out they were routing through his device just fine, and I plugged in an extra XBee I have to verify that in XCTU.

I would still love to know what that error was about...