Unable to checkout workflow - Support and Troubleshooting

Unable to checkout workflow Issue  Unable to checkout workflow in the workflow editor

Cause The workflow was checked out by a user and the sys_id of the user is missing in the instance.

Resolution Workflow was checked out by a user whose sys_id is not valid anymore in the instance.

Check the workflow versions, check if there is a record on which the 'checked out by' is empty and 'checked out' was showing a date value. Whenever someone checks out a workflow, related 'checked out' field on the workflow version will show up a timestamp(or date). When the above record is deleted from the wf_workflow_version table, checkout option will be enabled on the workflow. OR

As a user, impersonate the user found in wf_workflow_version table who checked out the workflow, and delete the checked out version using that user As an admin, you can also force checkout the workflow and delete the checkout version