### Problem Originally reported: https://gitlab.com/gitlab-com/dev-sub-department/section-dev-request-for-help/-/issues/8 POST `/api/v4/projects/<id>/fork` returns `409 Conflict` response with error message: `Unable to save project. Error: Invalid request` The error message is very obscure and needs to be improved. ### Root cause The root cause was a misconfiguration of `gitlab_rails['object_store']`. `"uploads" => { enabled: false }` was missing and we used the default value `true` for that. I suspect that we tried to send an object to object store, but the store was returning an error. ### Proposal 1. Improve error message by adding extra details (like exception class, possibly the backtrace) 2. Try to reproduce the misconfiguration error and find a better way to report this problem.