Could be a bug related to MR2 MP2
Check this release notes.

Client status is displayed incorrectly in the Symantec Endpoint Protection Manager console
Fix ID: 1677244
Symptom: Client status is displayed incorrectly on the Home page Status Summary, but correctly on the Clients tab.
Solution: Corrected the query to retrieve client status from the database.

http://service1.symantec.com/SUPPORT/ent-security.nsf/docid_p/2007121216360648

If you have configured any scan , then on the home tab pick any client which has scan failure
go to the client. open the interface click on logs check scan logs. see if that scan completed or failed.

this should give an idea if ever its a bug or not.
 

Not clear about the version    "Hi, i am using SEP MR MP2". If you could let us know the correct version.

Sorry, typo there - MR4 MP2

thanks!

As Rafeeq told the error what you are telling is fixed in RU5

Ref:Release notes for Symantec Endpoint Protection 11.0.x and Symantec Network Access Control 11.0.x 

So pls upgrade your SEPM to RU5
Below doc can help you in this
Migrating to Symantec Endpoint Protection 11.0 RU5

Hi All,

Thanks for your comments. I shall update to MR5 and see how that goes.

I shall report back status shortly.

Thanks.

Hi All,

Thanks for your comments. I shall update to MR5 and see how that goes.

I shall report back status shortly.

Thanks.