Before a Core HR sync reads or writes a single employee, the connector first loads a set of reference lookup tables it needs, things like departments, unions, pay schedules, and rate codes. If a row in one of those lookup tables has a blank required value, or if two rows collide on the same key, the connector logs a specific message naming the lookup and the row, then the entire setup step fails, and the run stops before any employee is touched.
Because this happens before any employee is processed, you should not see sync activity at all for that run, on either a read or a write. The very last message in the log for this failure just says "Failures on Preload." That line by itself does not name a lookup, a row, or a value. The useful detail is always in the message or messages logged immediately before it.
Error Messages
| Message text | Direction | Occurs when | Outcome | Fix |
|---|---|---|---|---|
| Failures on Preload | Read and write | Any one of the setup steps that run before employees are read or written reports a failure, for example a lookup logged a duplicate or missing-value error. | Sync stopped. No employees are read or written for this run. | Do not act on this line alone. Scroll up to the message or messages logged right before it. |
| The Core HR Provider encountered a duplicate [lookup name, for example Department, Union, or Pay Schedule] with key: '[the duplicate row's key or value]' in the Employee Service. Contact support to resolve this issue. | Read and write | A lookup table used to build the Employees sync, departments, unions, pay schedules, rate codes, and roughly two dozen similar lookups, has two rows that resolve to the same key. | That row is skipped from the lookup, but the setup step still fails overall, so the sync stops before any employee is processed. | In Core HR, find and correct the duplicate lookup row named in the message. |
| The Core HR Provider encountered an error loading [lookup name]. The item with key: '[the row's key, an internal Core HR record identifier]' must have a valid [field name, usually "Value", occasionally "Description" or "Rate Code"]. You may need to look for items with a Null/Empty value to identify the item causing this error. Contact support to resolve this issue. | Read and write | A row in one of those same lookup tables is missing the value the connector needs, for example a department with no code or a pay schedule with no name. | That row is skipped from the lookup, but the setup step still fails overall, so the sync stops before any employee is processed. | In Core HR, find the lookup row named in the message and fill in its missing value. |
Confirming the Error
- Open the sync execution for the run in question in Sync History.
- Open the step for the Core HR connector.
- Find the Employees entity row within that step.
- Check the Failures column on that row. A non-zero Failures count for this family means setup failed before any employee was processed, so the Added, Updated, and Unchanged columns for that row will read zero. This is different from the Errors and Warnings columns, which count problems on individual employee records that were still processed.
- Open the entity's message list. The last entry will read "Failures on Preload," which names nothing actionable by itself. Scroll back to the message or messages logged immediately before it. Those are the ones naming the lookup and the row at fault.
Duplicate Lookup Value
- Read the duplicate message and note the lookup name and the key or value it reports.
- In Core HR, open the setup area for that lookup type, for example Departments, Unions, Pay Schedules, or Rate Codes.
- Find the two (or more) rows that share that key or value and correct, rename, or merge the duplicate so each row is unique.
Missing Lookup Value
- Read the missing-value message and note the lookup name and the internal record key it reports.
- In Core HR, open the setup area for that lookup type and locate the row matching that key. The message tells you which field is blank, most often labeled "Value," occasionally "Description" or "Rate Code."
- Fill in the missing value on that row.
Confirm the fix: Correct the row in Core HR, then re-run the sync. Check Sync History again for the same Employees row. Failures should now read zero, and Added, Updated, or Unchanged should show non-zero activity.
When to Escalate
If any of the following occur, you may need to reach out to Arcoro support for additional assistance.
- Both the duplicate-value and missing-value messages end with "Contact support to resolve this issue." Before escalating, confirm the lookup and row named in the message are real.
- If the named row already looks correct, or the fix does not clear the failure on the next run, escalate.
- If "Failures on Preload" appears in the log with no duplicate or missing-value message directly before it, escalate immediately. That means the failure did not come from a lookup data problem.
- When escalating, include the exact duplicate or missing-value message text (lookup name, key, and field), the connector or Product Configuration name, the entity (Employees), and the sync run date or ID.