Steps to reproduce:

1. I'm running SNMPWALK on Linux

snmpwalk -c xxxx0x0 -v2c 10.xx.xx0.4x .1.3.6.1.4.1.2021.11

Result:
OutPut is -

UCD-SNMP-MIB::ssIndex.0 = INTEGER: 1
UCD-SNMP-MIB::ssErrorName.0 = STRING: systemStats
UCD-SNMP-MIB::ssSwapIn.0 = INTEGER: 0 kB
UCD-SNMP-MIB::ssSwapOut.0 = INTEGER: 0 kB
UCD-SNMP-MIB::ssIOSent.0 = INTEGER: 2930 blocks/s
UCD-SNMP-MIB::ssIOReceive.0 = INTEGER: 0 blocks/s
UCD-SNMP-MIB::ssSysInterrupts.0 = INTEGER: 4137 interrupts/s
UCD-SNMP-MIB::ssSysContext.0 = INTEGER: 5056 switches/s
UCD-SNMP-MIB::ssCpuUser.0 = INTEGER: 0
UCD-SNMP-MIB::ssCpuSystem.0 = INTEGER: 0
UCD-SNMP-MIB::ssCpuIdle.0 = INTEGER: 99
UCD-SNMP-MIB::ssCpuRawUser.0 = Counter32: 16651930
UCD-SNMP-MIB::ssCpuRawNice.0 = Counter32: 0
UCD-SNMP-MIB::ssCpuRawSystem.0 = Counter32: 6315963
UCD-SNMP-MIB::ssCpuRawIdle.0 = Counter32: 368750011
UCD-SNMP-MIB::ssCpuRawWait.0 = Counter32: 29611282
UCD-SNMP-MIB::ssCpuRawKernel.0 = Counter32: 0
UCD-SNMP-MIB::ssCpuRawInterrupt.0 = Counter32: 0
UCD-SNMP-MIB::ssIORawSent.0 = Counter32: 2767676658
UCD-SNMP-MIB::ssIORawReceived.0 = Counter32: 8637330
UCD-SNMP-MIB::ssRawInterrupts.0 = Counter32: 598633661
UCD-SNMP-MIB::ssRawContexts.0 = Counter32: 3462064737
UCD-SNMP-MIB::ssCpuRawSoftIRQ.0 = Counter32: 155225
UCD-SNMP-MIB::ssRawSwapIn.0 = Counter32: 0
UCD-SNMP-MIB::ssRawSwapOut.0 = Counter32: 0
UCD-SNMP-MIB::systemStats.64.0 = Counter32: 0
UCD-SNMP-MIB::systemStats.65.0 = Counter32: 0
UCD-SNMP-MIB::systemStats.66.0 = Counter32: 0
UCD-SNMP-MIB::systemStats.67.0 = INTEGER: 40

Expected:
Getting error like -

Cannot create item: Invalid SNMP OID at position 34