Version 1.7.1477 of JobScheduler has a bug that causes a repeat order to hang in particular circumstances.
Workarounds are available.
The issue occurs in Version 1.7.1477 when a job chain has a shell job at the first node and only one repeating order.
The bug and workarounds is described in detail in JS-1172.
We are working on publishing a bug-fix release as soon as possible.