Can not intstall any extension via Paper- UI after upgrade to OH2b5

Hi, I’m using OpenHAB2 on an ODROID C1. I had installed 2b4 with the apt-get method, what worked fine. The version I used was the “stable” version, offline mode.

After apt-get to beta5 I’m not able to install anything with the Paper-UI. The operation times out.
In the openhab.log is a [WARN ] message stating [url.mvn.internal.AetherBasedResolver] - Error resolving artifactorg.apache.karaf.bundle:org.apache.karaf.bundle.core:jar:4.0.4:Could not find artifact org.apache.karaf.bundle:org.apache.karaf.bundle.core:jar:4.0.4

Also, all versions shown in the Paper-UI are shown as 2.00b4