Despite the message in the log, it isn't a problem when viewing task status, it's when you try to display the sequential task itself (i.e. the General tab). When you click on the sequential task within the console tree, after the timeout period (e.g. 90 seconds) it displays "
The following error occurred on the page 'edSequentialSWDTask.aspx' Unknown or unspecified error" and it logs the "Failed in populating the status g
rid" message. It never loads to the point where you can see the task tabs or navigate to any of them, status included.
In addition, I don't think it has to do with the size of evt_aex_swd_execution because other sequential tasks and regular software delivery tasks work fine. The sequential tasks that do load contain the same number of tasks and load within 15 seconds. Since this times out after 90 seconds (or 120 if I change it), I don't believe it is heavy load. I think it is likely some type of corruption, but everything I've looked at appears fine.
I've check item state and references, I can view as xml or export it, and I can view the properties. All of the security settings look fine and are unmodified. The audit history shows no unexpected entries. "Open in New Window" behaves the same way, timing out and then displaying the error.