The little circular arrow?
This is normal, particularly if you recently installed the deck. It’s a sign that some of the media is syncing in the background. It could take a while, depending on your machine, your internet speed, firewalls, etc.
For the MCAT deck a pretty ‘normal’ amount of time is maybe 10-15 minutes, though I have seen it take longer.
While that’s taking place in the background, you may notice that some media doesn’t display appropriately just yet. That will resolve as the sync takes its time and completes itself. The initial sync just takes a bit longer, though all subsequent syncs typically take a couple to a few seconds, generally.
If you run into any problems, though, feel free to reach out and happy to be of further help. 