elDoc versions overview:
As a general rule, we strive to keep backwards compatibility between minor versions (e.g. 5.x to 5.y) so you can upgrade without any configuration file changes or IDP or BPM re-configuration needs.
But in case any backwards compatibility changes come even with minor version upgrade (e.g. 5.0 to 5.1) - we always mention that in Release Notes, so during upgrade - please make sure you have checked Release Notes for any breaking changes.
There are breaking changes between major versions (e.g. 3.x to 5.y), please review all Release Notes for the intermediate version when you upgrade from the older version of the elDoc system to the latest.
General rule: make sure you have a valid backup of the database before performing any upgrade.