Can't remove files/folders

I’m not able to delete files / folders.
When I try to, system show the message "Error removing file …"
This is a new installation nextcloud, on a clean server with the new database.
Please help

In Google Chrome console i get error "DELETE http://domain/remote.php/webdav/Nextcloud%20Manual.pdf 403 (Forbidden)

Does the server user Nextlcoud is running as have write permissions on the data folder and files.