Today, I spent my entire work day trying to find the solution to this error.
When I would launch a web project from Visual Studio, IIS Express would fail to load. The error reported was:
Failed to register URL "http://localhost:10000/" for site "Portal3" application "/". Error description: Access is denied. (0x80070005)
I started down the obvious track of checking permissions. IISExpress would operate just fine when run as
Administrator, but not as my normal user. I was an administrator on the local machine, so that didn’t make any
sense.
The only thing I had done that morning was use Disk Cleanup to delete all my temp files and archived error
reports. I checked %temp%\iisexpress. I checked my *.config files in Documents\IISExpress over and
over. I restored configs from backups. I read many potential solutions, some as crazy as not being able
to use a user name with “bg” in it.
I tried an older iteration of the web application. It worked. I tried other web projects in the
solution. They worked. At this point, I was the only developer in my team who had a single web project
that wouldn’t launch.
Then, late as usual, I finally remembered the Windows Event Viewer. IISExpress was logging these two events:
Event ID: 2269: The worker process for app pool 'Clr4IntegratedAppPool', PID='7536', failed to initialize the http.sys communication when asked to start processing http requests and therefore will be considered ill by W3SVC and terminated. The data field contains the error number. EventID 2276: The worker process failed to initialize correctly and therefore could not be started. The data is the error.
That lead me down a totally different troubleshooting path. While doing so, I set up a new website in IIS on
port 8085. Oddly, my new websites and application pools didn’t refresh after being created, which led me to
think there was even more wrong with my workstation. An IISRESET resolved that problem and I was able to
browse to the web project using IIS.
So IIS would work on port 8085 but IISExpress would not work on port 10000. And IIS would work for any other
project on seemingly any other port.
In a comment on one of the web posts that I read, I saw this command:
netsh http add urlacl url=http://localhost:10000/ user=everyone
I’d only ever used NETSH maybe once or twice for some obscure reason, but the inclusion of “ACL” in the command was
encouraging. Amazingly, the command worked! Although I was happy, I was also disappointed that I
wouldn’t be able to see what the value was previously so I could find out the root cause.
So I ran:
netsh http show urlacl
And that displayed a bunch of entries that included these as well (User and SDDL changed):
Reserved URL : http://127.0.0.1:10000/
User: Me
Listen: Yes
Delegate: No
SDDL: D:(A;;GX;;;S-1-5-21-)
Reserved URL : http://127.0.0.1:10001/
User: Me
Listen: Yes
Delegate: No
SDDL: D:(A;;GX;;;S-1-5-21-
Reserved URL : http://127.0.0.1:10002/
User: Me
Listen: Yes
Delegate: No
SDDL: D:(A;;GX;;;S-1-5-21-)
Where did these come from? I ran netsh http delete urlacl url=http://localhost:10000/
and removed the entry and confirmed IISExpress stopped working. Then I ran
netsh http delete urlacl url=http://127.0.0.1:10000/ and IISExpress started working again.
Something had added ACL entries for ports 10000-10002 that were conflicting with my web project, which was trying to
run on port 10000 using IISExpress. How did they get there? I looked in Add/Remove Programs to get a
clue as to what could have added these entries. Who’s to blame? The Azure SDK. Azure Storage
Emulator uses ports 10000-10002 and creates reservations for them. This was installed during my attempts at
getting command-line Web Publishing to work.
I never would have known anything about this unless I had read the Azure SDK documentation. The error message I
was given said nothing about port conflicts. nothing led me down that path at all. And it’s entirely
possible no one else would have this problem unless they were running IISExpress on port 10000.
But the important takeaway from this is that NETSH will allow you to create reservations for port numbers that may
conflict with other applications.