FWIW I can confirm the same issue occurring, currently observing this for example in northern Germany for a lot of tiles around the z=12 zoom level (but I can see errors up to z=7); the tiles seem to be valid files but empty. Curiously the DuckDuckGo variant also shows missing tiles but they generally seem to differ from what we observe on our own application. The missing tiles do not seem to simply correspond to specific CDN hosts unfortunately, I get some valid tiles as well as some broken ones from sat-cdn1/2/3/4.

We can confirm this here from Germany, have been seeing issues since about 1 AM UTC in increasing amount (although that may also be due to our traffic fluctuations). Besides the "alert internal error" we also have had connection aborts, no response after our 6 second time out and the occasional "HTTP 503 Unavailable" error. Some servers in the DNS rotation seem to be affected more than others though. Apple developer status unfortunately doesn't show anything either and the normal apple status only a resolved issue between 3:16 and 4:45 which doesn't match our logs at all.

At least in our ASC account the message now has disappeared, so given the questions here I assume this was a bug with a slightly concerning message and nothing more, the Stackoverflow discussion also contains an Apple Support response at https://stackoverflow.com/a/63506812/605221

And as a notice for others (also added that to my feedback filing), we're also getting an increased amount of "service unavailable" (HTTP 503) since friday, February 7th, again

Good note, filed a feedback under #7571546 as well to give it some visibility there.

We've been managing to work around it by using a retry, so its not as persistent as before, but yeah; we're still seing connection resets every now and then, which we did not observe before the outage. A simple retry seems to have solved the issue thus far though.

Same here from Germany, started Jan 24, 2020 12:11:01 PM UTC (going on for 3 hours at this point). We get a mix of connection timeouts and service unavailables depending on the actual server answering.It seems that some, but not all, Apple servers are affected by this (maybe a single DC?). In any case we found that some servers still respond; if you can force your servers to use a different DNS entry (buy.itunes.apple.com is resolving differently for different callers), you might still be lucky enough to get validations. Note however that you should closely monitor this then; if you hardcode IP addresses, these may become invalid at any time⚠ so this is a temporary workaround at best. In any case that is just saving a sales event that happens to fall in the middle of our outage, so everyone is grasping at straws probably.