Why am I seeing REPOINT_CROSSWALK_SPECIFIED_IN_MULTIPLE_REF_ATTRS in my data loader error log for a relations upload?

Question:

We were carrying out some loads in our SIT 1 tenant (H9uyPXKbmTJ40ew) and some records failed to load with an error saying, "Crosswalk is used for repoint in multiple ref attributes". 

We could not understand what the error was about from the error file, and it would be highly appreciated if you could help us with the same. 

CommonException: Code: REPOINT_CROSSWALK_SPECIFIED_IN_MULTIPLE_REF_ATTRS; Message parameters: []. Crosswalk is used for repoint in multiple ref attributes. CrosswalkTO {type: configuration/sources/AMS, sourceTable: null, value: 12228261_12228261_12228261_12228261} is used for repoint in multiple ref attributes. Current ref attribute has crosswalks: [configuration/sources/AMS/12228261_12228261_12228261_12228261] and is specified inside incoming entity with crosswalks: [configuration/sources/AMS/12228261]. Another ref attribute with the same crosswalk is specified inside incoming entity with crosswalks: [configuration/sources/AMS/12228261].

• HasAddress Relations with AddressType as Gold was loaded first:

• HasAddress Relations with other AddressTypes were loaded after the Gold:

In this case, we are using surrogateCrosswalks

 "surrogateCrosswalks": [
              {
                  "enforce": true,
                  "source": "configuration/sources/AMS",
                  "attributes": [
                      "configuration/entityTypes/Location/attributes/AddressLine1",
                      "configuration/entityTypes/Location/attributes/AddressLine2",
                      "configuration/entityTypes/Location/attributes/City",
                      "configuration/entityTypes/Location/attributes/StateProvince",
                      "configuration/entityTypes/Location/attributes/Country",
                      "configuration/entityTypes/Location/attributes/Zip/attributes/Zip5"
                  ]
              }
          ],

Answer:

The repointing problem is related to the fact that many of the same relations are updated under the same request. So, the behavior depends on the:

1. 1. data condition already in the tenant
   2. race conditions inside a platform

If the requirement is to have several values under the relations' attribute under the same crosswalk, then it can be achieved with the grouping feature.

Example