On rare occasions your data or installation can become corrupt, preventing you from entering the Minecraft Marketplace. If you encounter an Invalid Session Error, your best option is to reinstall Minecraft.
How to fix Invalid Session Error in Minecraft Marketplace
- Back up your saved data*
- Uninstall Minecraft
- Reinstall Minecraft
- Download your saved data
*See Back up Minecraft: Bedrock Edition Worlds to learn how to save your world data.