Upgrade Jackrabbit 2.1.6 to Jackrabbit 2.20.6

I need to update the jackrabbit version from 2.1.6 to 2.20.6, so I want to know the best way to do that. I saw that there is an option with importing/exporting data to XML ( https://jackrabbit.apache.org/archive/wiki/JCR/BackupAndMigration_115513344.html ), but I'm not sure how to do that. So' if you know how to perform a jackrabbit upgrade on this way, or some other way please let me know.

Note: Currently when I start the APP with jackrabbit 2.20.6 I get the following error:

Caused by: java.lang.IllegalArgumentException: Invalid namespace index: 2
    at org.apache.jackrabbit.core.NamespaceRegistryImpl.indexToString(NamespaceRegistryImpl.java:366) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.persistence.util.BundleReader.readBundleOld(BundleReader.java:221) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.persistence.util.BundleReader.readBundle(BundleReader.java:149) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.persistence.util.BundleBinding.readBundle(BundleBinding.java:152) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.persistence.pool.BundleDbPersistenceManager.readBundle(BundleDbPersistenceManager.java:927) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.persistence.pool.BundleDbPersistenceManager.loadBundle(BundleDbPersistenceManager.java:889) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.persistence.bundle.AbstractBundlePersistenceManager.getBundleCacheMiss(AbstractBundlePersistenceManager.java:766) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.persistence.bundle.AbstractBundlePersistenceManager.getBundle(AbstractBundlePersistenceManager.java:750) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.persistence.bundle.AbstractBundlePersistenceManager.exists(AbstractBundlePersistenceManager.java:563) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.version.InternalVersionManagerImpl.<init>(InternalVersionManagerImpl.java:162) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.RepositoryImpl.createVersionManager(RepositoryImpl.java:526) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.RepositoryImpl.<init>(RepositoryImpl.java:314) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]
    at org.apache.jackrabbit.core.RepositoryImpl.create(RepositoryImpl.java:616) ~[org.apache.jackrabbit.core-2.20.6.jar:2.20.6]

You may want to try to identify the Jackrabbit version that apparently made in incompatible change here; maybe a fix is possible. So try 2.2., 2.4. etc.