
This is a known product defect. The localization resources for Japanese languages aren't properly compiled.
This issue has been addressed in the following release:
Enterprise Vault 12.0.2 Release
Enterprise Vault 12.1
Accessing to the EVOM (Enterprise Vault Operations Manager) via the path http://<Enterprise Vault server>/MonitoringWebApp causes a server error when accessing from a Japanese locale client.
This issue occurs regardless of the server's locale configuration. Even if the server is in an English locale, this issue occurs if the accessing client is Japanese.
ETrack: 3875240