After trying everything else in this thread and failing (I got both errors people are reporting), I finally found a way.
I turned off the Windows 10 firewall to see if that would help, and it did! I was able to fully log in on the US servers and get to my characters.
Turning the firewall back on immediately after did not prevent me from logging in again, so I guess it just needed to get through once in order to get everything working again. Super weird.
I was able to resolve my issue after updating NVIDIA drivers to latest.
Same issue here. US Servers seem to be part of the issue.
Glad it worked for you! 
For anyone still having problems, try turning off your Windows 10 firewall. (You can turn it back on if it works) They did tell me in response to my support ticket that they believe the issue has to do with the firewall after the most recent Windows 10 update. Hopefully it works for everyone else!
This worked for me:
If you’ve re-installed recently…
Windows Firewall change settings for diablo 3 being allowed through Public and Private.
Add Diablo 3 32-bit version, allow for public and private.
Launch 32 bit version, log out launch 64-bit version.
You should hopefully be good to go.
If you’re running a pi-hole, whitelist battle.net
I haven’t done anything to fix the issue but I was able to log in just now. I’m not too sure if it was something on their end that they just fixed or what but I figured I would post and let everybody know to give it another try and see what happens.
Alas still no go on my end.
It can’t be a firewall issue because again, I can log into the Asian/EU servers just fine. There would only be an issue with American servers if its being jammed from Blizzards end in this comparable situation. I don’t understand whats so complicated about this.
EDIT:
Okay so I disabled my anti-virus software to get this to work. So what kind of digging into my system are you doing that I can’t log in Blizzard, that my Antivirus triggers an error?
I can’t seem to log in and when I do the game is completely lagging badly and then kicks me out
I was finally able to get the game to launch by enabling the 32 bit version, logging in to see my characters, logging out, then switching back to 64 bit. Took a minute but it loaded. Turning firewalls on/off made no difference. I did update my Radeon video drivers and software. Thanks everyone on the forum for their tips. Hope you get in game soon.
Working for me now.
Just wanted to provide some info on what I did. I am not sure if what I did actually resolved my issue or if it was the constant retries that did it.
Haven’t played in years, wanted to play again.
Logged-in via battle.net app gave me the 395000 license issue error. Other regions (Asia and Europe had no issues at all).
I noticed that 2/3 three steps passed (step 2 is the authenticated was green and had a tick), but on step 3 where it was retrieving my hero/character list; this is where it failed and gave me that 395000 every time.
I did flush my IP (ipconfig /release, /renew, /dnsflush) and still same issues.
Read the suggestion about logging-in directly into the game. So I tried that.
I was already logged into my battle.net app, launched the game, got the expected 395000 error.
Alt tabbed out to windows, logged-out of battle.net completely, even right click and shut down the app if it was showing in my task manager (which it was).
Went back into my game, and entered my credentials, entered my blizzard authenticator code (I think I re-synced first) before I did this.
I got a different error now; the 300016 error.
I repeated this 3 times, and on the third or forth time I was able to log in successfully!!! On subsequent failed attempts I got the 300016 error btw.
I am going to start playing now, hopefully I won’t be disconnected and be block by this 395000/300016 error again. I wanted to come back here to post, in case it may be of any help to others.
I also checked my game was active in my account. I did not try the firewall thingy.
I am still not logged into my battle.net app, but I did have to sign-in here to post this comment.
I followed similar steps here and I was able to get my wife’s account logged in. I opened the game, killed the battle.net client completely, and then repeatedly tried to log in to the account through the Diablo game itself. After 4 or 5 failed logins due to the 300016 error it finally went through.
This also worked for me and on the first try. I didn’t have the 395000 error, just the 300016 error. I alt-tabbed, logged out of the app then logged in directly via the game client. Thanks!
It worked for me too on my second attempt.
Hay guys, i got the same problem with america server, but not Asia or euro.
luckily I fixed it .
I think it’s a firewall issue. I am using wireless connection. the previous setting for my network was public, after changing to private, I was able to log in.
try to check your network or firewall settings, add D3 as your trusted program, etc.
hope this is helpful
I hope they fix this soon too - I’ve gone the extra step of uninstalling and reinstalling the game too.
I’m having the same problem but i have been on within the last 6 months. Rebooted, repaired, reinstalled. disabled my firewall, still error it says, "Diablo failed to load… I don’t know what else to do 
Im having the same issue as well… 395000… I tried switching to the 32 bit as well… no luck… I did have a pop up from my firewall to let Diablo 3 retail run, but it didnt make a difference either.
Still having the same issues this morning also from last night. Came back and bought the 2 new expansions and was never able to log onto the US servers. Had no issues logging into the EU servers and playing a character. Tried firewall off/on and changing DNS to google.
WinMTR Statistics
| Host | % | Sent | Recv | Best | Avrg | Wrst | Last |
| 192.168.1.1 | 0 | 349 | 349 | 0 | 0 | 5 | 0 |
| 96.120.116.21 | 0 | 349 | 349 | 6 | 10 | 208 | 12 |
| po-302-1210-rur02.sims.mn.minn.comcast.net | 0 | 349 | 349 | 6 | 10 | 208 | 13 |
| be-33-ar01.roseville.mn.minn.comcast.net | 0 | 349 | 349 | 7 | 12 | 216 | 13 |
| be-13367-cr02.350ecermak.il.ibone.comcast.net | 0 | 349 | 349 | 13 | 21 | 226 | 23 |
| be-1402-cs04.350ecermak.il.ibone.comcast.net | 0 | 349 | 349 | 17 | 22 | 219 | 22 |
| be-2401-pe01.350ecermak.il.ibone.comcast.net | 0 | 349 | 349 | 17 | 21 | 222 | 23 |
| 173-167-56-238-static.hfc.comcastbusiness.net | 0 | 349 | 349 | 17 | 27 | 316 | 24 |
| ae1-br01-eqch2.as57976.net | 6 | 265 | 250 | 0 | 307 | 4706 | 63 |
| No response from host | 100 | 70 | 0 | 0 | 0 | 0 | 0 |
| No response from host | 100 | 70 | 0 | 0 | 0 | 0 | 0 |
| 137.221.68.83 | 0 | 349 | 349 | 57 | 64 | 263 | 65 |
| 24.105.30.129 | 0 | 349 | 349 | 57 | 62 | 266 | 62 |
im getting this error, been close to a year that i logon to D3,
was gonna play the new season with friends this friday… I tried uninstalling d3 2 time, and uninstalling everything (blizzard + d3)
no work
32 bit doesnt work
overwatch work,
and europe or asia server work.
I even tried connecting using different dns (i normally use google one) and even try connecting using a vpn from another location to confirm it wasnt an ISP problem on my end…
Blizzard better fix that before friday or I will be disappointed…