Hi there!
I am using event aggregator and it kinda worked but now my imports just hang. I removed them all and only added one back but that only shows the bar on top but nothing is happening there. It shows the preview though and a manual check of the REST API returns events.
I am using the custom URL feature to pull events from other event calendar instances.
I also enabled debugging but nothing is actually logged. (I might try producing an error on purpose just to check that)
I can provide more information with a private reply if you want (like URL of the calendar to be imported)