Summary:

An issue may arise on a customer's Sage CRM install whereby enabling the Exchange synchronisation for Contact records results in errors.

On failing, a HTTP 500 error in logged in the exchangeConfiguration log.

ERROR [http-apr-11009-exec-1]: 28-Apr-2014 15:57:27.222 url: http://CRM-SERVER/sdata/crmj/crmExchange/-/contacts/$syncSource?trackingId=5fa807d2-9326-4a71-bde8-f01a21a51972&count=100, error: com.sage.crm.httpconsumer.error.SageHttpConsumerException: POST on http://CRM-SERVER/sdata/crmj/crmExchange/-/contacts/$syncSource?trackingId=5fa807d2-9326-4a71-bde8-f01a21a51972&count=100 failed: 500, action: ESTABLISHING_CONNECTION_CRM_ENDPOINT

If 'Sync contacts' is set to No, the sync completes without problem.

Solution:

In this instance, the issue was caused by duplicate field metadata entries being present on the Custom_Edits table. Examining the table revealed that there was a second entry with a Colp_Colname of "Pers_PersonId" and a Colp_Entity of "Person". Removing the duplicate entry resolved the issue.