Magento 2.4.3 > Migration > Aheadworks RMA > Error "JSON Serialization in Handler

M 1.9.3.10 -> M 2.4.3 Migration overall successful migration. Only for expert into this topic, as assistance. Future work possibel.

A) Fix an error in data handler resulting front end error JSON Serialization from Field Data:

aw_rma_entity.print.label field

(Example: a:10:{s:9:"firstname";s:7:"Susan";s:8:"lastname";s:7:"Foo";s:7:"company";s:0:"";s:9:"telephone";s:11:"017311111";s:3:"fax";s:0:"";s:13:"streetaddress";a:2:{i:0;s:26:"Teststr.";i:1;s:0:"";}s:4:"city";s:11:"Testcity";s:10:"country_id";s:2:"DE";s:8:"postcode";s:5:"10000";s:14:"additionalinfo";s:0:"";} )

A) Fix an error "missing id" while running aw_rma/config.xml

SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'owner_id' cannot be null, query was: INSERT INTO `aw_rma_thread_message` (`id`, `request_id`, `created_at`, `text`, `owner_type`, `owner_id`,
`is_auto`) VALUES (?, ?, ?, ?, ?, ?, ?)

SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'owner_id' cannot be null

C) Migration Tool Commands executed
bin/magento migrate:settings -a vendor/magento/data-migration-tool/etc/opensource-to-opensource/1.9.3.10/config.xml
bin/magento migrate:data -a vendor/magento/data-migration-tool/etc/opensource-to-opensource/1.9.3.10/config.xml
bin/magento migrate:data -r vendor/magento/data-migration-tool/etc/aw_rma/config.xml

D) Clean M2 Installation and working M1 Installation provided.

E) Result expected

RMA to orders are assigned. RMA Module works as expected.