Error Sending PDU. usmStatsNotInTimeWindows

Hello All- New user, new to the Manage Engine community. We are using an API AdventNetSnmp.jar and are receiving the error in the topic title when walking some of our Cisco switches. Quick web search produces the following:

usmStatsNotInTimeWindows

This is set when the engineTime specified is not within the timeWindow of agent. The engineTime is considered not within the timeWindow if any of the following is true.

If the agent's snmpEngineBoots value is equal to 2147483647.
If the request's snmpEngineBoots value differs from that of the agent.
If the difference between the SNMP request's snmpEngineTime and that of the agent is greater than 150.

This error is reported by the agent with its first varbind containing the OID ".1.3.6.1.6.3.15.1.1.2.0" and the value is a Counter giving the number of packets that have been dropped because of this error.

But this is all Greek. Can somebody comment? Also, please let me know if this is not the appropriate forum.

Many thanx.