After updating the patch, the game will blackscreen when I try to launch Classic Hardcore and it gives a windows error. I tried restarting my computer, verifying the files. Nothing works. I can launch WOTLK Classic just fine so it’s the patch that broke the game. I noticed some other users are also getting the same thing so please look into this asap. Thank you
Edit: Version is 1.15.0.52186
Same issue just get black screen. Doesn’t even get to character select or a login screen.
Posted this to the wrong sub forum. If you’re having this issue, I reposted the same topic under the classic bug forum to hopefully bring it to the devs attention.
Looks to be working now. I just loaded up both my era toons and hardcore toons without issue.
It is not fixed. Still getting blackscreen. It’s probably not affecting everyone.
If it’s not affecting everyone, then it isn’t server side it’s client side. Have you tried repairing the WoW Classic install from the launcher? Often times patches can corrupt during install for a myriad of reasons.
These types of errors are almost always an issue with your computer. Your best bet is to take this to the tech support forum, also be much more specific about your machine configuration if you post, as things like your processor, video card etc can impact issues like this.
Here things you can try
Okay so here is what I have tried so far.
Updated to latest version of windows. Check
Updated latest graphics drivers. Check
Check Hard drive space. 1TB free. Check
Try repairing/reinstalling WoW. Full Uninstall and Reinstallation of game and files. Check
Game still won’t launch.
Clearly this is an issue that only Blizzard can fix and is related to last nights patch. I’ve seen at least four other people post on this forum that they are having the exact same issue.
Same issue. Game not working. Repaired. No luck.
same issue, repaired, windows updated, Still can’t play. Anyone knows what to do?
Open a ticket with Blizzard, unless they can actually duplicate your issue, they will probably need at minimum some sort of bug trace.
I resolved from my end by setting “-d3d11” in command line argument.
Battlenet launcher → Game Settings → [x] Additional command line Arguments → use the command line argument: -d3d11 → restart Bnet → Click Play
Credits/source to u/H_Maddigan from classicwow subreddit!
I had the same issue and even the wow icon was not showing. I kept alt tabbing until it gave me the message to stop the process or wait for program to respond. I hit wait, waited a few minutes and it loaded. Haven’t had an issue since.
I resolved from my end by setting “-d3d11” in command line argument.
Battlenet launcher → Game Settings → Additional command line Arguments → use the command line argument: -d3d11 → restart Bnet → Click Play
Credits/source to u/H_Maddigan from classicwow subreddit!
Just want to add that this forces the client to use only DirectX 11 so I tried using d3d12 - which worked but set to DX12. Then I closed the game and removed the argument and the game is now launching fine. 
Can confirm this works! Thank you to everyone who contributed!
I was having an issue earlier where I could not launch any version of WoW. I would click Play on the Battle.net Launcher and I could see a blank application show up on my taskbar. If I clicked on the application, the screen would turn black. If I opened up the Task Manager it would say the application (listed as World of Warcraft) was not responding. I tried the simple fixes like restarting my computer and using the Scan and Repair tool on the Battle.net launcher. Those did not work. I eventually found a thread of people having similar issues in the past on AMD based systems. One of the Blue responses noted something about the game taking several minutes to launch.
Instead of closing the application when the Task Manager said the World of Warcraft application was not responding, I just let it sit there for several minutes. The game eventually started. Every time I tried to launch the game after that, it would do so quickly with no issue. Very strange issue with a strange resolution on my end.
That’s very strange but I’ll be sure to remember it if something like this happens again.