ValueError: Cannot assign id to field when saving form

The error message "ValueError: Cannot assign id to field when saving form" in Groovy typically occurs when trying to assign an ID to a field while saving a form. This error suggests that there is an issue with the code that is attempting to assign an ID to a field in the form.

To resolve this error, you can try the following steps:

1. Check the code where the form is being saved and look for any lines that assign an ID to a field.
2. Make sure that the field you are trying to assign an ID to exists in the form and is properly defined.
3. Verify that the ID you are trying to assign is unique and does not conflict with any existing IDs.
4. Ensure that the ID assignment is happening at the correct time and in the correct context within the code.
5. Double-check the syntax and formatting of the code to ensure there are no typos or syntax errors.

If the issue persists, it may be helpful to provide more specific details about the code and the context in which the error is occurring. This will allow for a more accurate diagnosis and solution.

Please note that without the specific code snippet or more context, it is difficult to provide a more precise answer.