Instances are not in sync

If the author and public instances are not using the same time you may see the following error when you publish content: 

info.magnolia.cms.exchange.ExchangeException: Message received from subscriber: 
Activation refused due to request arriving too late or time not synched between author and public instance. Please contact your administrator to ensure server times are synced or the tolerance is set high enough to counter the differences.

To resolve this issue, check the system time (server time) on both instances. Configure the servers to use Network Time Protocol (NTP) so that they use the same time and stay in sync.

If you still get the error, configure a higher activationDelayTolerance in the Activation module. This property allows for a time difference between the instances. The default value is 30,000 milliseconds (30 seconds). Try a higher value.