Michael, but according to dev_w1.log you are still with client 7.7.7. Did you check note 1357452? You didn't answer if there was recent DB upgrade - maybe you should review all steps cause something is missing here.
Also:
C Try to connect (DEFAULT) on connection 0 ...
C *** ERROR => Connect to database failed, rc = -10709 (Connection failed (RTE:Database name is missing))
[dbsdbsql.cpp 139]
Check note 39439 and try to create DEFAULT connection in same way.
Regards,
Matus