I have a Upgrade Dir 600 vB5E. I followed this guide to install OpenWRT.
I can login and its saying Powered by LuCI Master (git-15.233.47308-791ca8b)](http://luci.subsignal.org/) / OpenWrt Chaos Calmer 15.05
But in Luci->Flash operations->Flash new firmware image booth SysUpgrade images are saying: The uploaded image file does not contain a supported format. Make sure that you choose the generic image format for your platform. It does not matter if I use Firefox or Chrome. I have to find a 16.x image to jump from Chaos Calmer to Lede? But history says there is no OpenWRT 16.
Edit: I didnt want to use the image from mega.nz, because the source is unclear. But it worked. It downgrades to Barrier Breaker. Then I can upgrade to 18.06 (meaning: the 18.06 image is accepted as a sysupgrade), but after that the router doesnt boot anymore. Maybe the 17.01 is really the last working image for this router. My girlfriend is here, she wants to watch a film and I can't fiddle with the router anymore. Tomorrow I will start a new try from the Systemrecovery upwards. I will write the outcome.