# Problems After a Mapping Change

This page contains only the checks to perform when the result after a mapping change is not what you expected. For the normal behavior of saving a mapping, first read [What Happens When a Mapping Is Changed](https://manual.vtenext.ch/books/exchange-connector-vtenext-Hfx/page/what-happens-when-a-mapping-is-changed).

## Records disappeared from Exchange

If the mapping was just saved, wait for resynchronization to complete before intervening. Original vtenext records are not deleted by the mapping change.

## Records return but some fields are empty

Check that the field is mapped, the field type is compatible, the value exists in vtenext and the primary e-mail is still mapped correctly. For mapping rules, see [Editing a Mapping](https://manual.vtenext.ch/books/exchange-connector-vtenext-Hfx/page/editing-a-mapping).

## Duplicates are created

<div id="bkmrk-do-not-force-additio" style="background:#fde8e8;border-left:5px solid #b42318;padding:14px 16px;margin:16px 0;color:#7a1b14;">**Do not force additional synchronizations**  
Do not keep changing the mapping until the cause has been identified.</div>Check whether the previous resynchronization had finished, folders were also changed, users were reconnected at the same time, or bulk imports were performed.

## Returning to the previous mapping

Use the screenshot or documentation saved before the change. Saving the old mapping again also starts another resynchronization; it is not an instant undo.