I'm getting the message "maximum number of historical concurrent system-wide searches has been reached current=10 maximum=8", and searches go to paused without running.
When I navigate to Activity->Jobs and set App=All I can see about a dozen jobs with "Dispatched at" dates of 24 hours ago or more, up to 2 months in some cases. The Status of all of these jobs is Done. The jobs are all of the form "| summarize maintain=..." or "| summarize tstats=...".
There are also some with a Dispatched at date of 1/1/70 - I'm guessing that these are actually new jobs with a null Dispatched at date. The status of all of these jobs is "Running(0%)".
By deleting some of the "summarize ..." jobs, I can get the paused jobs to start - but why is this necessary? Why are these old jobs still alive? And why was current more than the maximum?