If you are some of the thousands waiting to get their hands on build 10051 of Windows 10 Technical Preview for phones, you are probably experiencing lots of server issues.
Microsoft has taken to the blog with an update on the matter. Long story short: it is going to be another two hours before the situation is resolved.
If, however, you are on the Fast Track for the Insider program and already on build 9941 (the old one), you may be able to sneak in line and get the update. Our Lumia 635 is installing the update as we speak, and a few others are also getting updated.
We will post a refresher when Microsoft resolves the issue. In the meantime, we'll try to get some screenshots and videos up shortly of the new build to tide you over. Here is the excerpt from the updated Microsoft blog post:
"We discovered this morning that there was an error in the database for provisioning record data, which is required for new phones to join the Fast Ring through the Windows Insider app. The team has been working to correct it but the load on the provisioning data servers has made all operations extremely slow. To fix the issue, we are taking the service offline and updating the provisioning record data for all 5100 phone POPs. It will take approximately 2 hours for us to make the update, and validate that everything is working. This is a different service from Windows Update, so Insiders who are currently on 9941 should be able to update their phones if they are already in the Fast ring. If they are in the Slow ring they will encounter the same issue with provisioning data. We apologize for the delay on this and are working to ensure it never happens again."
So grab a coffee as it's going to be a loooong day (or night).
Source: Windows Blog