For a "complete" 1.36 experience, you need the DLCs that were available at that time. Newer DLCs released after 2019 (like Iberia or West Balkans) will not work if the game is downgraded to 1.36. SCS Software
If you are using a non-Steam version, ensure you are downloading from a reputable source. Always scan .exe and .zip files for viruses before installation. Troubleshooting Tips download ets2 1.36 all dlc
A free addition to the Vive la France! DLC, adding the beautiful Mediterranean island. For a "complete" 1