I just installed 4.8.3 (Never used UE4 before), and was wondering about the extended times I’m facing when loading projects. An example, I created a blueprint third-person project using the template, but it took 15-20 minutes to load the project into the editor. I’m running Windows 10 Pro x64, quad core processor (AMD Phenom II x4 945), and eight gigs of ram, if it matters. So is this 15-20 minute wait just par for the course? Do I just need to learn to be more patient? 
Is this happening just when you load it the first time, or always? 
Quite interestingly, it seems to have stopped as soon as I posted a question about it. The example I mentioned now opens up in a reasonably small amount of time, a minute or two. But all of today I was getting times so long it made me think the Editor had frozen. Perhaps UE does some housekeeping at first that takes longer. I’m going to cross my fingers and hope it keeps performing.
Just an additional end-note, I tried to copy the project I was having the most problems with (referenced above) to a different folder, and was informed some of the files were corrupted and unreadable. I think the external drive I was saving to has started to fail, so that would explain the load times.