If the DVD menus no longer  work, in this case please follow these steps:

1. Restore the firmware via usb key, the procedure to follow is explained in the article below:

https://zappiti.uservoice.com/knowledgebase/articles/1906222--firmware-restore-firmware-procedure-via-usb

2. Once the firmware restoration is finished, do a factory reset of your player, the procedure is explained in the article below: