the Gateway Status log of the Enterprise Server is flooded with this error com.sepasoft.production.tags.collector.storeddata.TagRecords; 
local class incompatible: stream classdesc serialVersionUID = 1, local class serialVersionUID = 8132203291859736287


This means the two gateways have different serialVersionUID  for the same class so it cannot send over the network.

It is a requirement to run the same MES versions and Support Package on Enterprise and (all) Site(s)

please follow the guide to upgrade. 

Sepasoft Modules can be downloaded from