IIS - Unable to start debugging on the web server. The address is not valid for this context

Issue:

I was unable to start debugging of web server or attach to process due of error:

Unable to start debugging on the web server. The address is not valid for this context.

Resolution:

I figure out that I need to Enable 32-Bit Applications in Application Pool settings:




IIS 7.5 : HTTP Error 500.21 - Internal Server Error - Handler "PageHandlerFactory-Integrated" has a bad module "ManagedPipelineHandler" in its module list

Solution:

This is is because ASP.Net was not completely installed with IIS. 

To fix this, simply run the following command at the command prompt

%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -i

If I had been on a 32 bit system, it would have looked like the following:

%windir%\Microsoft.NET\Framework\v4.0.21006\aspnet_regiis.exe -i

Once this has been done, Restart IIS and run the web application. 

WCF REST Service Hosting Error : HTTP Error 500.21 - Internal Server Error

HTTP Error 500.21 - Internal Server Error
Handler "svc-Integrated" has a bad module "ManagedPipelineHandler" in its module list in IIS 7.5


Solution:

If you see this error you haven't installed the prerequisites for ASP.NET 4.

Try this:

Step 1. Open Visual Studio Command Prompt
Step 2. Type the following: aspnet_regiis.exe -i
Step 3. Run the command

Try your service again... it should be working :-)

This command basically installs the necessary ASP pieces to get your service up and working!