This article will address the "java.lang.NullPointerException" error when running a GMU migrateOut command.
Execution failed. Reason: Internal Server Error. Detail: java.lang.NullPointerException
The root cause appears to be the use of the Asymmetric Encrypt/Decrypt assertion in the service(s) which has been used in the GMU migration out of the source Gateway. While this should proceed without issue, there appears to be a defect in the Gateway-specific-version of that assertion that causes issues with GMU migrations.
This article applies to all supported versions of the API Gateway.
To resolve, update the Asymmetric Encrypt/Decrypt assertion to 1.0.0 from the Gateway-version-specific version (i.e. 9.2). This will allow the GMU to succeed again. If you do not have version 1.0.0 (or the latest version), please open a support case requesting access to that version, and link to this article in the case description for reference.