Admin UI after Nightly update not accessible

Hello,
I use Homegear Nightlys since a long time now. Usually I updated Homegear via:
wget -O /tmp/InstallNightly.sh
https://downloads.homegear.eu/InstallNightly.sh && bash /tmp/InstallNightly.sh
… which is obviously outdated.
My current version is 0.2.0-1321-dev for admin-ui and 0.8.0-3468 for Homegear.

Now I tried to update my installation to the newest Nightly via the current command:
wget -O /tmp/HomegearInstaller
.sh https://downloads.homegear.eu/HomegearInstaller.sh && bash /tmp/HomegearInstaller.sh

After the update everything was working fine except the Admin UI, which was not accessible anymore and throwed following error message:

Does anyone know how to resolve this issue?
Thanks in advance!
Carsten