> For the complete documentation index, see [llms.txt](https://docs.elentra.org/technical/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.elentra.org/technical/developers/troubleshooting/docker.md).

# Docker

## Session Errors After Upgrading

Problem: You experience errors related to Redis and being unable to read the session data.

![](/files/-M9-xMdQh5nKc-1-oBko)

* Make sure that you have started the docker environment with the `--build` flag by running

  ```
  docker-compose up -d --build
  ```