JOC Cockpit throws exception on removing starter with Runtime

Current Situation:
On deleting the JobStreams starter with runtime JOC Cockpit throws the exception:

com.sos.schema.exception.SOSJsonSchemaException: $.jobstreamStarters[0].nextStart: integer found, string expected

How to reproduce:

• Create a job stream with the starter.
• Add a runtime to the starter.
• Click on the action menu of the starter and delete the starter.
• It SOSJsonSchemaException is thrown.

Desired Behaviour:
JOC Cockpit should not throw an exception on removing the starter with Runtime.