Central Admin not found 404 error

Question

HI All,

All of sudden Central admin site went down and throws 404 error. When I look at log found this

"PublishingHttpModule.PostAuthorizeRequestHandler(): Unexpected exception while analyzing URL: System.TypeInitializationException: The type initializer for 'Microsoft.Office.Server.Utilities.HttpUrlEncoder' threw an exception. ---> System.IO.FileLoadException: Loading this assembly would produce a different grant set from other instances. (Exception from HRESULT: 0x80131401)     at System.Linq.Enumerable.Contains[TSource](IEnumerable`1 source, TSource value)     at Microsoft.Office.Server.Utilities.HttpUrlEncoder..cctor()     --- End of inner exception stack trace ---     at Microsoft.Office.Server.Utilities.HttpUrlEncoder.TryConvertUrlPart(String input, UrlPart part, UrlConversion conversion, String& result, Exception& parseException)     at Microsoft.Office.Server.Utilities.HttpUrlBuilder... f048609e-c4f9-6068-2d33-78e892c4ba96"

Any suggestion to fix this issue?

Answer 1

Hi SamDany,

Open the web.config of the Central admin,search about "LegacyCasModel" key , then just set LegacyCasModel to false instead of true

From: 
<trust level="Full" originUrl="" legacyCasModel="true" />

To: 
<trust level="Full" originUrl="" legacyCasModel="false" />

i hope this will help you

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Best Regrads, Ahmed Madany MCTS @twitter http://twitter.com/ahmed_madany @Blog http://ahmedmadany.wordpress.com @LinkedIn http://eg.linkedin.com/pub/ahmed-madany/35/80/2b6

Answer 2

Hi,

This issue could cause by the SCOM’s APM component or 3rd Party monitoring tool on SharePoint server.

Client-side .NET Application Performance Monitoring (APM) is not supported for SharePoint.

To resolve this issue, deploy SCOM without APM or remove them from SharePoint server.

A blog with good information for your reference:

http://blog.bugrapostaci.com/2017/02/08/loading-this-assembly-would-produce-a-different-grant-set-from-other-instances-exception-from-hresult-0x80131401/

Here is a similar discussion thread, you can check the replies in it for more information:

https://social.technet.microsoft.com/Forums/en-US/5db05238-3c12-4e7e-af95-ca56545f0721/loading-this-assembly-would-produce-a-different-grant-set-from-other-instances?forum=sharepointgeneral

Best regards,

Linda Zhang

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