The problem is more and more curious. I have another schematic in which last week was an ideal_balun. But now there is only a PORT, GND and a varactor. As with the other schematic, the simulation runs after I opened the schematic and ADE. But if I check and save the schematic the simulation did not run and in the log I can read:
Warning from spectre in `ideal_balun', during circuit read-in.
WARNING (SFE-618): "input.scs" 76: Unterminated subcircuit. Terminating statement at the end of file.
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Error found by spectre during initial setup.
ERROR (SPECTRE-4080): There are no components in the circuit.
After closing and reopen ADE the simulation runs without problems.