Common error messages
This section is about the errors that might occur when you run the Data Migration Tool, and how to deal with them.
Source documents/fields not mapped
In rare cases, the message might mention
Destination documents or
Destination fields instead of source ones.
Some Magento 1 entities (in most cases, coming from extensions) do not exist in the Magento 2 database.
This message appears because the Data Migration Tool runs internal tests to verify that tables and fields are consistent between source (Magento 1) and destination (Magento 2) databases.
Install the corresponding Magento 2 extensions from Magento Marketplace
If the conflicting data originates from an extension which adds own database structure elements, then the Magento 2 version of the same extension may add such elements to the destination (Magento 2) database, thus fixing the issue.
-aargument when executing the tool to auto resolve errors and prevent migration from stopping.
Configure the Tool to ignore the problematic data
To ignore database entities, add the
<ignore> tag to an entity in the
map.xml file, like this:
Before ignoring entities by map file or using the `-a` option, make sure you do not need the affected data in your Magento 2 store.
Class does not exist but mentioned
A class from Magento 1 codebase could not be found in Magento 2 codebase during the EAV migration step. In most cases, the missing class belongs to an extension.
Install the corresponding Magento 2 extension
Ignore the attribute that causes the issue
For this, add the attribute to the
ignoregroup in the
Add class mapping using the
Foreign key constraint fails
Error message text
There are missing database records in the
parent_table to which the
field_id of the
child_table is pointing to.
Delete the records from the
child_table, if you do not need them.
To keep the records, disable the
Data Integrity Step by modifying the Data Migration Tool’s
Duplicates in URL rewrites
Target path in a URL rewrite must be specified by a unique pair of
Request path +
Store ID. This error reports two entries that use the same
Request path +
Store ID pair with two different
Target path values.
auto_resolve_urlrewrite_duplicates option in your
This configuration adds a hash-string to the conflicting records of URL rewrites, and shows the resolution result in your command line interface.
Mismatch of entities
The error occurs during the Volume Check step. It means the Magento 2 database record count of the document is not the same as in Magento 1.
Missing records happen when a customer places an order during migration.
Run the Data Migration Tool in
Delta mode to transfer incremental changes.