Property file:filename is deprecated starting LTS 2017 and an error message is generated when it is used in the code.
The error message below is generated when a permission audit report is requested:
2018-05-25 18:01:57,889 ERROR [RemovedProperty] Property 'filename' is marked as removed from 'file' schema, don't use it anymore. Return value from 'content/name'
file:filename is mentioned in class PublishByMail.
Using the widget Files triggers an error
Remove deprecated code for LTS 2017