Is there code in the UIPethernet library that can reset the processor ?

[PaulM47]

I'm using the latest UIPethernet and MQTT PubSubClient librararies on an Arduino Nano V3 board to receive MQTT control data from a local network broker. I've had problems with the broker being intermittent and seen the Nano board reset several times for no apparent reason. I've solved the MQTT broker problem and the reset problem appears to have gone away which suggests loss of connection to the MQTT broker causes something to reset the processor. The most likely culprit is the PubSubClient libarary but I thought I'd ask here just in case something in the UIPethernet library can cause the reset ?

Regards
PaulM