I helped a colleague with this just the other day, and it's quite interesting. The issue was that the Enterprise Vault Indexing Service on his Enterprise Vault 10 server would not start. He would get a pop-up saying that the service started, then immediately stopped. I had a quick look at the event log on the server, and spotted this:
Log Name: Symantec Enterprise Vault Source: Enterprise Vault Date: 30.10.2013 14:50:18 Event ID: 41299 Task Category: Index Admin Service Level: Information Keywords: Classic User: N/A Computer: L1-EV10-11.domain1.forest1.lab.quadrotech-it.com Description: The Indexing Service is pending initialization. Requesting additional time for initialization routines....
Log Name: Symantec Enterprise Vault Source: Enterprise Vault Date: 30.10.2013 14:50:39 Event ID: 41293 Task Category: Index Admin Service Level: Error Keywords: Classic User: N/A Computer: L1-EV10-11.domain1.forest1.lab.quadrotech-it.com Description: The Enterprise Vault installation is currently in maintenance mode and consequently unable to process your request. Maintenance mode was initiated because [System Administrator requested shutdown]. (ID: CORE_MAINTENANCE_MODE)
Log Name: Symantec Enterprise Vault Source: Enterprise Vault Date: 30.10.2013 14:50:39 Event ID: 41298 Task Category: Index Admin Service Level: Information Keywords: Classic User: N/A Computer: L1-EV10-11.domain1.forest1.lab.quadrotech-it.com Description: The Indexing Service has stopped (10.0.3.1090).
So, I thought: "Test environment, that's fine, let's reboot".
After the reboot... same issue! I happened across a forum post from earlier in this year, and whilst it doesn't explain things entirely, removing the two files did fix the issue.
Note: The only thing that changed recently was VM host upgrades, and VSphere Client Upgrades... and this seems to have been the only thing affected.