When the fields promoted do not become editable even after uploading the form multiple times, follow the steps given below:
- Delete the entire Form Library
- Delete the form’s Content Type from the the Site’s Content Types Gallery
- Remove the field from the InfoPath form entirely
- Publish the form (minus field) and uploaded it in Central Admin
- Re-add the field in InfoPath and published, again promoting the field in the same way as done before from Central Admin à Manage Form templates option
- Add the form’s Content Type to a new copy/version of the Form Library.
- Deactivate and re-Activate the feature for the form in the Site Collection Settings of needed.
- Added the form’s Content Type to the new Form Library
Follow this steps and this shall solve your problem.