Windows could not start the Citrix Command Center service on Local Computer. Error 1067: The process terminated unexpectedly.
Error occured during initialization of VM. NoClassDefFoundError. These are some of the messages being shown randomly when I noticed Command Center was offline and I tried to start the service.
Note: Command Center is now End of Life. NetScaler MAS is the replacement http://www.jgspiers.com/citrix-netscaler-management-analytics-system/
The logs showed some Java errors.
I then compared the Java JRE lib directory with a backup directory and noticed that there was 5 items more in the backup directory than what was in live. All .jar files.
The _jrebkup/lib directory contained more files than the live folder.
The next step was to copy the missing files across to the live lib directory.
After the copy had completed the Citrix Command Center service started.