Upgrade to version 2.3 from version 1.5
First perform all steps for upgrading from version 1.5 to 1.6, and then perform all steps for upgrading from version 1.6 to 2.0, and then perform all the steps for upgrading from version 2.0 to version 2.1, and then perform all steps for upgrading from version 2.1 to 2.2 and then all the steps explained in Upgrading to version 2.3 from version 2.2.
Upgrade to version 2.3 from version 1.4
First perform all steps for upgrading from version 1.4 to 1.5, and then perform the steps of upgrading from version 1.5 to 1.6, and then perform all steps for upgrading from version 1.6 to 2.0 and then perform all the steps for upgrading from version 2.0 to version 2.1, and then perform all steps for upgrading from version 2.1 to 2.2 and then all the steps explained in Upgrading to version 2.3 from version 2.2.