If you install Ektron 7.5.2 on an IIS 7.0 server, you may encounter 500.21 errors during the processing of requests. The symptoms I saw were as shown below:

You can see that the images for the buttons were missing. My first thought was that I had a permissions issue on the assets folder. But that was not reflected in the fiddler traces I was getting.

I had set the Pipeline mode to Classic in the AppPool that the application was running under:

This sets the Pipeline mode to classic which is what I wanted. But I was getting 500.21 errors complaining about a "bad module 'ManagedPipelineHandler'"

Then the light bulbs went on! Preconditions! And sure enough, the two handlers in the web.config file that referenced ManagedPipelineHandler has empty preconditions settings.

<add name="ek*" path="*" verb="GET,HEAD,POST" type="Ektron.ASM.EkHttpDavHandler.EkDavHttpHandlerFactory" 
modules="ManagedPipelineHandler" scriptProcessor="" resourceType="Unspecified" requireAccess="Script" 
preCondition="" />
<add name="ekdav" path="*" verb="OPTIONS,PROPFIND,PUT,LOCK,UNLOCK,MOVE,COPY,GETLIB,PROPPATCH,MKCOL,DELETE,
(GETSOURCE),(HEADSOURCE),(POSTSOURCE)" type="Ektron.ASM.EkHttpDavHandler.EkDavHttpHandlerFactory" 
modules="ManagedPipelineHandler" scriptProcessor="" resourceType="Unspecified" requireAccess="Script" 
preCondition="" />

As you can see, both of the above have preCondition="" I set both to have a preCondition of integratedMode and saved the changes and instant success!

This stems from the fact that these are managed code modules, leaving preCondition blank means to use the modules in both Classic and Integrated modes. Since we are running the application in Classic pipeline mode (ISAPI Mode) it was attempting to run these modules. Changing the preCondition to integratedMode tells IIS not to use the modules unless the pipeline mode is set to integrated.

Running in Integrated mode does not seem to work either, for other reasons, most of which I have not yet figured out, but this fix allowed me to at least run the application on Vista and IIS 7.0.

Cheers,

Robert Porter