How can I recovery the H2 database and why got this exception?

[Glenrodrigues]

Hello all, I am trying to recover h2 database for nexus 3.70.1

Setup:
Nexus Version: 3.70.1
H2 Version: 2.2.224
java Version: 11

Steps followed to recover H2 database
Step1

Scale Down the Pod and go into debug container

Step2

java -cp /plza/sonatype/nexus/system/com/h2database/h2/2.2.224/h2-2.2.224.jar
org.h2.tools.Recover
-dir /nexus-data/db
-db nexus

After above command. nexus.h2.sql file will be generated
/nexus-data/db/nexus.h2.sql
/nexus-data/db/nexus.h2.log

Step3

mv /nexus-data/db/nexus.mv.db /nexus-data/db/nexus.mv.db.broken

Setp4
java -cp /plza/sonatype/nexus/system/com/h2database/h2/2.2.224/h2-2.2.224.jar
org.h2.tools.RunScript
-url "jdbc:[h2:/nexus-data/db/nexus]"
-user sa -password ""
-script /nexus-data/db/nexus.h2.sql

Step5
Come out of debug pod and scale up the pod.

Error i got

` ... 48 common frames omitted
2025-12-08 11:15:09,079+0100 ERROR [FelixStartLevel] *SYSTEM org.sonatype.nexus.extender.NexusContextListener - Failed to start nexus
org.sonatype.nexus.datastore.api.DataAccessException:

Error querying database. Cause: org.apache.ibatis.executor.result.ResultMapException: Error attempting to get column 'ROLES' from result set. Cause: java.sql.SQLException: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize value of type java.util.HashSet<java.lang.Object> from String value (token JsonToken.VALUE_STRING)

at [Source: REDACTED (StreamReadFeature.INCLUDE_SOURCE_IN_LOCATION disabled); line: 1, column: 1]

The error may exist in org/sonatype/nexus/internal/security/model/CUserRoleMappingDAO.xml

The error may involve org.sonatype.nexus.internal.security.model.CUserRoleMappingDAO.read

The error occurred while handling results

SQL: SELECT * FROM user_role_mapping WHERE user_id = ? AND source = ?;

Cause: org.apache.ibatis.executor.result.ResultMapException: Error attempting to get column 'ROLES' from result set. Cause: java.sql.SQLException: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize value of type java.util.HashSet<java.lang.Object> from String value (token JsonToken.VALUE_STRING)

at [Source: REDACTED (StreamReadFeature.INCLUDE_SOURCE_IN_LOCATION disabled); line: 1, column: 1]
at org.sonatype.nexus.datastore.mybatis.DataAccessSqlSession.unwrapMyBatisException(DataAccessSqlSession.java:125)
at org.sonatype.nexus.datastore.mybatis.DataAccessSqlSession.selectList(DataAccessSqlSession.java:76)`