Draytek Vigor File System Invalid accessing the web interface

I have recently come across an issue I’ve not seen before. A Draytek 2862 router was rebooting itself every couple of hours. When I tried to get the web interface I got an error:
File System Invalid. The file system of the Web-based UI is inconsistent with router’s firmware. Please check the firmware version.

After a bit of trial and error I have found a solution.

The Solution

First, you need to download the latest firmware for the model you have.

Next you need to download Draytek’s Firmware Upgrade Utility tool.

Extract the firmware, and Draytek upgrade utility and then run the Draytek Firmware upgrade utility.

Enter the IP address of the Draytek, by default 192.168.1.1, but it may be different depending on your network.

Select the Firmware you have downloaded. Important note: select the firmware with extension .all. If you use the firmware with the extension .rst it will factory reset the Draytek.

Enter the admin password of the Draytek and click send.

Once I’d done this I was able to log into the Draytek as normal.

Hope this helps you solve the File System Invalid problem,