# Cannot start session because Docker image does not exist **URL:** \ **Category:** RenkuLab\ **Created:** [27 May 2025 15:54 UTC](https://renku.discourse.group/t/cannot-start-session-because-docker-image-does-not-exist/1155 "2025-05-27T15:54:38Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![lorenzo](https://avatars.discourse-cdn.com/v4/letter/l/4da419/32.png) [@lorenzo](https://renku.discourse.group/u/lorenzo)\ **Post date:** [28 May 2025 09:57 UTC](https://renku.discourse.group/t/cannot-start-session-because-docker-image-does-not-exist/1155/2 "2025-05-28T09:57:27Z")
Hello @schymans , I looked at your project and I couldn’t find anything obviosuly wrong. I checked the jobs for building the Docker image ([the “start with options” page](https://renkulab.io/projects/ba_math_gen-16/et-data/sessions/new) will always link to the last pipeline when it fails – in this case, [here is the last job](https://gitlab.renkulab.io/ba_math_gen-16/et-data/-/jobs/768178)) and noticed it was failing while installing the requirements. I played around a bit and got the same failure when using your requirements file ([reference](https://gitlab.renkulab.io/lorenzo.cavazzi.tech/test-new-20250528/-/jobs/768276)), but I could fix it by removing a couple of dependencies that were triggering the failures ([reference](https://gitlab.renkulab.io/lorenzo.cavazzi.tech/test-new-20250528/-/jobs/768281)). I wonder if new versions of those libraries are causing conflicts when solving the full tree of dependencies since you could build the image 10 months ago. The easiest fix would be pinning the dependencies to older versions (tip: GitLab automatically links each line on the requirements file to the corresponding pypi page; you can easily open the libraries [from your requirements file here](https://gitlab.renkulab.io/ba_math_gen-16/et-data/blob/master/requirements.txt), check the version history, and pin them to ~10 months ago). I hope this helps! --- _[View the full topic](https://renku.discourse.group/t/cannot-start-session-because-docker-image-does-not-exist/1155)._