Dear Experts,
I am facing a strange error in dynamic deadline configuration. I have configured deadline "Latest End" to be calculated using expression. I have already created three container attributes with initial values and configured them in the expression:

Container Elements:
ENDDA TYPE SYDATUM Default Value 30.09.2017
TIME TYPE SYUZEIT Default Value 12:00:00
TIMEZONE TYPE TZNZONE Default Value UTC
But: when starting the workflow it crashes directly with error message "Deadline determination failed":

I have tested different constalations in expression setting (with other time, without time, standard timezone %ZONLO% expression a.s.o.) without success.
Static expressions (Workitem or Workflow creation date) are working fine.
Hope one of you Experts can help me here.
Best Regards & Thank you
Christoph