This is a common error but easily recovered
Please use this JapharFlasher, new Universal DreamUp working with all DM Original and Clone boxes
1. Connect via serial using NULL Modem cable (DM800HD) or Mini USB Cable (DM800SE) and a direct connection with Ethernet from Dreambox to Router.
2. Load japharflasher, select your com port, then click connect and power on DM800HD/DM800SE
3. When initialized it will display http serial mode on LCD display and show dhcp ip, once ip is displayed dreamup has served its purpose and now its in flash mode
4. Flash a new image via your internet browser (192.168.x.xxx address on LCD display) and flash a new image as normal.