As Jory noted, this error message is one which can occur for many reasons, but generally, it means what it says: in whatever context the datatype was attempting to be looked up, it was unable to find the definition of the Pod, meaning the post type or taxonomy etc.
Software is complex. It involves millions of calculations which change in behavior depending on action and context.
For this reason, when reporting an error, it will help find a resolution if you can be as specific as possible:
- When you say you were adding a new Post Type and Taxonomy, do you mean you were adding new definitions on the Pods Admin > Edit Pods screen, or you were attempting to add content to the data types you specified before?
- If creating new types, what were you attempting to name the Post Type and Taxonomy? Does behavior change if you change or simplify the names?
- Are you able to see the post type and taxonomy you created before?
- Do things change if you log out and back in; clear browser and hosting caches? Clear Pods cache in Pods Admin > Settings? Rebuild Pods in Pods Admin > Settings > Tools?
- Are you running the latest version of Pods?
- Are there any errors in the PHP error log or browser JavaScript console?
- Do things change if you disable other plugins; switch to a default theme?
