For security reasons we wanted to chnage the service accounts username for all the IIS application pools and SharePoint service , so we created a new user named "Staging.user", and i define it as a managed account inside SharePoint. and then we chnage the iis application pool and the SharePoint services to use this account, as follow:-
but after that some site collections will raise an 403 Forbidden error when trying to access them, while other will work. For example we have a list where all the views will work but the create form will raise 403 HTTP error , so we can edit the list items and delete them, but if we click on create form we will get 403 forbidden error.. so can anyone adivce what is causing this ? Thanks