Ascension paths (Psionic, Synthetic, Genetic, and Cybernetic) were reworked into full Tradition trees rather than just a pair of perks.
Saves from version 3.5 or earlier are generally not compatible with 3.6 due to the massive changes in ship logic and traditions. File: Stellaris.v3.6.0.Incl.ALL.DLC.zip ...
If you are looking for how to play this specific version, here are the major highlights and changes introduced in the 3.6.0 update: Ascension paths (Psionic
A new ship class, the Frigate, was introduced. These are small, specialized ships designed to carry torpedoes and hunt larger targets. Troubleshooting & Technical Notes was introduced. These are small
If your query is about how to get the file working, please be aware of the following: