MPAD: AD Exception: 00002083: The attribute exists or the value has been assigned. (4379098)

The attribute exists or the value has been assigned. The attribute was: (o)
Error during CreateObject
Object DN: CN=User3 Lab2,OU=Lab2,DC=target3,DC=local
Object ID: 6
Result code: AttributeOrValueExists
AD Exception: 00002083: AtrErr: DSID-03152080, #1:
    0: 00002083: DSID-03152080, problem 1006 (ATT_OR_VALUE_EXISTS), data 0, Att a (o):len 14

Object attributes:
    adminDisplayName = 8ae726bc-b470-4d73-accc-3fdc3ec3717a
    objectClass = user
    unicodePwd = ****
    userAccountControl = 66048
    proxyAddresses = SMTP:u3lab2@source3.local
    proxyAddresses = X500:/o=/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=8ae726bc-b470-4d73-accc-3fdc3ec3717a
    targetAddress = SMTP:u3lab2@source3.local
    accountExpires = 9223372036854775807
    codePage = 0
    company = quest
    countryCode = 0
    displayName = User3 Lab2
    givenName = User3
    legacyExchangeDN = /o=/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=8ae726bc-b470-4d73-accc-3fdc3ec3717a
    mail = u3lab2@source3.local
    name = User3 Lab2
    O = Support
    physicalDeliveryOfficeName = Bali
    sAMAccountName = u3lab2
    sn = Lab2
    userPrincipalName = u3lab2@target3.local
    o = Support
    adminDescription = Created By DirSync
 (The attribute exists or the value has been assigned.)

The error AD Exception: 00002083 was generated in the course of attempting to add an attribute that has already been mapped/existed.

From the sample error, it was caused by the attribute (o):
O = Support

o = Support

Steps to verify and resolve the error:
1) At your Settings > Advanced > Mapped Fields, search for the attribute O (uppercase) and o(lowercase).

2) Do you see the default attribute O (uppercase) already mapped (see image attached below)?

3) If the default O(uppercase) mapping is already available, you do not need to add another mapping for o (lowercase).