After creating anew blueprint, when attempting to edit it, the changes are unable to be saved and a 403 (forbidden) error appears in the browser console
Environment
Liferay DXP 7.4
Resolution
A 403 error generally indicates that something is blocking an API from getting through.
One possibility for this can occur if a web server sits in front of Liferay.
Since the API endpoint call is a PATCH request, there may be something in the web server that is blocking the API
There may be an HTTP options method in the web server that is disabled. If so, enabling it should unblock the API and resolve the 403 error.