I have a wordpress site set up locally on a homestead version 6 vagrant box. Its been working fine for ages but suddenly I'm getting this error at the bottom of the screen
Failed to communicate with Zend Server. See why.
Can anyone shed any light on this? I don't even know what it would need to connect to zend? Totally confused.

Homestead 7.1 introduced Z-Ray support which is a Zend debugging tool. It is possible that you are running this version.
Later updates to the Homestead source code have hidden this unless you switch it on in the Homestead.yaml file.