ServerUpdate 2.3.7 to 2.3.8 from source - configuration lost


Dear all,
I am running urbackup on my small server at Ubuntu Bionic Beaver.
Installed from source (V2.3.7). Runs fine till update.
Download 2.3.8, doing some ./configure, make and make install.
Now I visit --> admin login lost, and no other Clients are in there anymore.

Every help is welcome.

Best Regards