问题
On the development server I use IIS Veresion 7.5.7600.16385
And a Service compiled for .Net 4.5.1, Any CPU
The service works fine on the development server (Win Server 2008 R2).
On the client's production server however I get strange problems:
(Same IIS Version, same OS version)
As soon as I set "Enable 32-Bit Applications" the service's URL is no longer accessible in a browser. (Page not available)
(I need the 32Bit mode because the service uses some legacy COM components)
What may cause this problems?
Any ideas, hints, suggestions?
Edit
More Details:
The "IIS Worker Process" is running as "w3wp.exe *32"
There is a ClickOnce Installation in the same Application Pool which behaves the same: works ok in 64 bit, not accessible if 32Bit set to true.
In fact all pages of this 32Bit App-Pool produce the same behaviour (HTTP 500) page not found.
回答1:
Step 1: Enable Logging in IIS
In Order to enable better error messages and log files in IIS you must install two Features:
Control Panel->Programs and Features->Turn Windows features on or off
You'll need two features installed:
WebServer->Common Http Features->HTTP Errors
WebServer-> Health an Diagnostics->HTTP Logging
Step 2: Analyse Error Messages
With HTTP Errors enabled I got a more verbose message when I accessed any page in the 32Bit App Pool:
HTTP Error 500.19
DynamicCompressionModule
ErrorCode 0x8007007e
Step 3: Decode Error Code
I used Microsoft Exchange Server Error Code Look-up to convert the ErrorCode into something more useful:
C:\Users\combyte>err 0x8007007e
as an HRESULT: Severity: FAILURE (1), Facility: 0x7, Code 0x7e
...
ERROR_MOD_NOT_FOUND winerror.h
The specified module could not be found.
It turned out, that a specific DLL was not installed. In my case the installation of WSUS (Windows Server Update Services) installed a 64Bit version of DynamicCompressionModule (C:\Windows\system32\inetsrv\suscomp.dll) only.
Solution1
Remove/Disable the XPress compression scheme from the IIS configuration (for all pages/app-pools) using this command:
%windir%\system32\inetsrv\appcmd.exe set config -section:system.webServer/httpCompression /-[name='xpress']
Solution2
Disable loading of the xpress module in IIS config file C:\Windows\System32\inetsrv\config\ApplicationHost.config for 32Bit App-Pools:
add attribute preCondition="bitness64" to the xpress module in section <modules>:
<add name="DynamicCompressionModule" lockItem="true" preCondition="bitness64" />
Solution3
Install the 32Bit version of suscomp.dll(from a 32 Bit Installation of WSUS) into %windir%\SYSWOW64\inetsrv\
来源：https://stackoverflow.com/questions/30206989/service-not-accessible-when-enable-32-bit-applications-set-to-true