When you download some of the default canned reports or custom report from Report Center, the first column is missing in the downloaded report.
The issue was discovered after a previous upgrade on Web Security Service (WSS) Reporting infrastructure.
The issue is now resolved. The portal was updated on December 2nd 2016 and the update contains a fix to address this issue. If the issue persists, please contact Symantec Technical Support.
There are two potential workarounds:
(1) Use "Forensic Report" or "Full Log Details", but this report does not provide any graph option.
(2) Download access logs from WSS [Portal] > [Service] > [Reporting] > [Log Download]. Setup BC Reporter-Standard version and process the downloaded access logs. You can generate or build your reports from BC Reporter.