If the timezone is a partial hour (like 5.5 for India), or if the timezone in the user profile is manually changed to a partial hour, trends will show an internal error.
Issue also may be related to a corrupt Shard in the database.
This has been identified as a product defect. Change Request TF00508596 has been raised for this to fixed in a future release or cumulative patch of Unified Communications Analyitics
Manually set the timezone in the User profile (click on the logged in name - top right corner of the Web UI | User Profile | Time zone) to a whole hour and save settings.
This cannot be set globally but only per user.
Note: The the issue is not due to the timezone, then it may be a corrupt Shard in the UC-Analytics Database. Please enable extended logging by following this article KB 146055 and provide the log files to Quest Software Technical Support for analysis.