From the srnd,
"Distributed transactions with the Java Transaction Manager are used to replicate Configuration Data Store data in high availability deployments. The way it works is that when both servers with Databases components are operational, configuration data store changes, such as skills and resource groups, are written to both the servers with Database components. If one server with a Database component is down, configuration data store changes are not possible."
So it looks like after the reboot of secondary the primary was not able to access the CDS on the secondary resulting in blocking any configuration changes, the condition seems to have cleared after a reboot of both nodes.
If this is a regular occurance I would check out to see if all the components are IN_Services specially the
CCX Database service also turn up the ADM_CFG - Debug and LIB_CFG to Debug and check for any clues in MADM logs.
Hope this helps.
Shirish