validation rule on change filedocument

I have a entity system.fileDocument with a validation rule on the name, this rule is working fine when a create the object, and try to upload the document for the first time. the object is then save in the database (commited). Then when I modify that object the validation rule is not working anymore ! I can upload another document that will completely bypass the validation rule. I need to use validation rule for security purpose, any suggestion? Thanks
1 answers

You could use an on change action where you do the validation in a custom microflow. Note though that since filedocument is a system entity you can not set those on the entity itself. So on every location where you can change the name of the filedocument you should set this on change microflow to trigger.