SNMP attribute got - Data not obtained -

I added a SNMP attribute from MIB browser that OID=.1.3.6.1.4.1.15.0.0.3.0 ( .1.3.6.1.4.1.15.0.0.3 by manual )and got logs as below:

01:31:06:031 MEAM: CAM : SNMP response code 2
01:31:06:031 MEAM: CAM : Scalar SNMP Data Collection started for a-wb39vvwu8p0i5
01:31:06:046 MEAM: CAM : Value obtained for .1.3.6.1.4.1.3028.1.1.2.2.3is 4
01:31:06:046 MEAM: CAM : Value obtained for .1.3.6.1.4.1.15.0.0.3is null
01:31:06:046 MEAM: CAM : Value obtained for .1.3.6.1.4.1.15.0.0.3.0is null
01:31:06:046 MEAM: CAM : Error occurred when inserting data into database for OID Info{TYPE=0, ATTRIBUTEID=10000005, ATTRIBUTENAME=.1.3.6.1.4.1.15.0.0.3, ERROR_OCCURRED_DURING_DATACOLLECTION=true, RESOURCEID=10000016, VALUE_OF_OID=Could not get value.}
01:31:06:046 MEAM: CAM : Error occurred when inserting data into database for OID Info{TYPE=0, ATTRIBUTEID=10000007, ATTRIBUTENAME=.1.3.6.1.4.1.15.0.0.3.0, ERROR_OCCURRED_DURING_DATACOLLECTION=true, RESOURCEID=10000016, VALUE_OF_OID=Could not get value.}

( .1.3.6.1.4.1.15.0.0.3 really has valid value return when I use other MIB browser)
How to fix this problem?
Thanks in advance.