We don't have any recent fixes or bug reports related to this.

It would happen if something went wrong during a previous execution and adTempus lost track of the state of the instance.

You should be able to find the instances it thinks it's waiting on: hold the Shift key while right-clicking the job, and the context menu should have a "Diagnostic Info" command at the bottom. Select this and it will give you a list of the instances that adTempus thinks are active. You can then go look for them in the Execution History Query (or directly in the database) and see if there is something weird about them.

If you find the instance(s) in the Execution History Query and they show in an active state, you can try terminating them (right-click, Terminate). Depending on what's gone wrong, this may get things back on track and make adTempus stop thinking they're still running.

If you can't find the instance in the Console or terminating it doesn't work, you should be able to clear the problem by restarting the adTempus service, if you can do that at a moment when it won't disrupt the rest of your processing.

Moving forward, I recommend you turn on diagnostic logging for the adTempus server. If the problem happens again, make a copy of all the server logs as soon as you notice the problem (so we don't have to worry about them rolling over) and then open a support case and send us the logs. We may be able to see from the logs what happened to get the previous instances stuck.