> For the complete documentation index, see [llms.txt](https://docs.release.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.release.com/guides-and-examples/running-instances/troubleshooting/image-pull-backoff.md). # ImagePullBackoff error How to debug an ImagePullBackOff error An ImagePullBackOff error means that an instance could not start because the image to build that instance could not be pulled from the image registry. This is often a temporary error, so restarting the instance will be attempted. After each unsuccessful start, the delay before the next attempt to restart is increased. ## Steps to debug and fix An ImagePullBackOff error is usually the result of one of the following issues: **The build failed** Try to kick off a new build. You can trigger a new build by clicking **Apply** under "Apply Latest Configuration" in the **Settings** tab. **The Docker Hub integration failed** If you're pulling images from Docker Hub, you might not have set your credentials for Docker Hub. Make sure you've followed the correct steps to [integrate Release with DockerHub](/integrations/integrations-overview/docker-hub-integration.md). **There is a typing error in the service definition** Double-check your service definitions. A typing error or incorrect name can cause an ImagePullBackOff error if the specified image does not exist. **A network glitch** This is rare, but it can happen. Try again after some time and the problem may resolve itself. **Using underscores in the Release YAML file** Use dashes instead of underscores in your Release YAML file. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.release.com/guides-and-examples/running-instances/troubleshooting/image-pull-backoff.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.