It may be due to Adeptia Suite is unable to connect with your back end database, check the back end database connection. If the issue still persist, contact your system admin.
How to enable clustering?
On the Administer tab, go to Setup > Application Settings > Update System Properties.
Expand Load Management.
Set the value to Yes of the abpm.cluster.enable property.
Go to the …/AdeptiaServer/ServerKernel/etc folder.
Open quartz.properties file in Notepad.
Adjust the value of the parameters - threadCount and misfireThreshold. For example: org.quartz.jobStore.misfireThreshold = 60000, where 60000 is the default value. org.quartz.threadPool.threadCount = 50