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IIS Support Blog
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ASP.NET Core: 503 Server has been shutdown

MattHamrick's avatar
MattHamrick
Icon for Microsoft rankMicrosoft
May 26, 2023
We've encountered a few support cases where customers, usually after some time, have an ASP.NET Core application hosted in IIS in-process that starts returning this "HTTP 503 Server has been shutdown...
Updated Jan 22, 2025
Version 4.0
503
ASP.NET Core
IIS
in-process
JamesHartley's avatar
JamesHartley
Copper Contributor
Aug 17, 2023

Matt, you saved my life with this post! I've been banging my head against the wall for weeks trying to figure out why my Blazor app was crashing so often with a 503 error. I had an unnecessary second builder in my startup.cs.