If these errors are occuring while running the .asp pages then below is the fix that will make things working for you.

1. Error as displayed in the browser: The server failed to load application. Check Eventlog for more details.

2. System log in the eventvwr - W3SVC: The server failed to load application '/LM/W3SVC/1/ROOT'. The error was 'Class not registered'.

3. Event Viewer Application Log for MSDTC CLIENT
Event Type: Error
Event Source: MSDTC Client
Event Category: (10)
Event ID: 4427
Description:
Failed to initialize the needed name objects. Error Specifics: d:\comxp_sp3\com\com1x\dtc\dtc\msdtcprx\src\dtcinit.cpp:215, Pid: 2536
No Callstack,
CmdLine: C:\WINDOWS\System32\dllhost.exe /Processid:{xxxx}

4. Component Services -> COM+ in MMC, it will throw error.

This means that COM+ on your system is corrupted and it is not able to communicate with msdtc. Also it is not able to get to the IIS Components/Packages in your COM+.

Solution
1. Fix MSDTC:

a. Go to the command prompt
b. Change directory to C:\%windir%\system32
c. Type: msdtc -uninstall
d. Restart PC
e. Go to the command prompt
f. Change directory to C:\%windir%\system32
g. Type: msdtc -install

2. After, msdtc is installed (Component Services -> COM+ in MMC will not throw any errors). Delete and re-register IIS Components/Packages in the COM+ by following the below steps:

IIS related package in Component Services MMC
1. IIS In-Process Applications
2. IIS Out-of-Process Pooled Applications
3. IIS Utilities

Steps
a. In the Command Prompt, go to %windir%\system32\inetsrv folder
and run >rundll32 wamreg.dll, CreateIISPackage command

b. run >regsvr32 asptxn.dll

c. Then reset IIS using iisreset command, then re-open Component Services MMC to verfiy the IIS Components/Packages are recreated.

The above steps should make your .asp pages render properly!!!!!

If you are using Windows Vista OS & SQL Server 2005 on your local system and if you are having a hard time to connect to <Machine-name>/SQLEXPRESS SQL Server with error message - "Can't connect to SQL Server", then the culprit is SQL Express 2005 SP1.

Download SQL Express 2005 SP1 from the below site and try reconnecting, you will say c'mon, don't tell me this was the issue :)

http://www.microsoft.com/downloads/details.aspx?FamilyId=11350B1F-8F44-4DB6-B542-4A4B869C2FF1&displaylang=en

Error in Visual Studio:



Follow these steps when you are running your VS program in debug mode,
a. Right click your project name -> go to properties.
b. On the left page, click on Debug Tab.
c. Check the Enable unmanaged code debugging checkbox.
d. Your code should run in debugging mode.

I was deploying my .aspx page that shows SSRS reports on Microsoft Report Viewer Control. After deploying the website, the report came successfully but the dundas charts weren't showing up.

After struggling for a long time, following steps i had to perform showed up the charts:

a. Copied the following dundas dll's to this location - 'C:\Program Files\Microsoft SQL Server\MSSQL.x\Reporting Services\ReportServer\bin'

- DundasRSChart.dll
- DundasRSChartDesigner.dll
- DundasWebChart.dll

b. Added the following code to the 'rsreportserver.config' file at 'C:\Program Files\Microsoft SQL Server\MSSQL.x\Reporting Services\ReportServer' location (inside the <Extensions> element):

</Service>
<Extensions>
<ReportItems>
<ReportItem Name="DundasChartControl" Type="Dundas.ReportingServices.DundasChart,DundasRSChart" />
</ReportItems>
<Delivery>

c. Added the following code to the 'rssrvpolicy.config' file at 'C:\Program Files\Microsoft SQL Server\MSSQL.x\Reporting Services\ReportServer' location (Make sure the following <IMembershipCondition> tag exists within the element <CodeGroup>):

</CodeGroup>
<CodeGroup class="UnionCodeGroup" version="1" PermissionSetName="FullTrust" Name="DundasChartControl" Description="This code group grants FullTrust to DundasChartControl assemblies."> <IMembershipCondition class="StrongNameMembershipCondition" version="1" PublicKeyBlob="0024000004800000940000000602000000240000525341310004000001000100d
16006505277d0860ce7d429331480cb3b9711481cd51213259cf3b106e30156f5ef48262e0154e862fa
05374e6c7cef5c4daa95b2272a73e503f0e5077c6b71a24176e67eadbff8e8765742f022e317194571de
05d0ac9a4fca62fd355854ebe5a38969a831030018edad7d7405dd23d0710c9faf95acf16a4a14003bada
5be" />
</CodeGroup>
</CodeGroup>
</CodeGroup>
</PolicyLevel>

Refer to this site for more details: http://support.dundas.com/Default.aspx?article=1107

This made my day. The charts showed up with a surprise.

In my web app, i was displaying the SSRS report using Microsoft Report Viewer Control. On loading the web app to view the report, was getting this error:

"The permissions granted to user 'NT AUTHORITY\NETWORK SERVICE' are insufficient for performing this operation. (rsAccessDenied)"

Found the following solution, thought of sharing:

a. Go to Report Manager under "http://localhost/Reports".
b. Click on Properties tab.
c. Go to Security options.
d. Choose New Role Assignment.
e. Add in the 'Group or user name' -> 'NT AUTHORITY\NETWORK SERVICE'.
f. Assign 'Browser' role to 'NT AUTHORITY\NETWORK SERVICE' user.

This should fix the problem. I was able to see my SSRS reports in my web app.

Breaked my head figuring out the above mentioned issue. It looked silly to me because it was just a normal Win2k3 server. Then why wouldn't it execute the exe's that i copied from another machine.

After browsing through the internet for a while, the below solution worked for me.

SOLUTION:
As i had copied the exe file from another machine, right clicked the exe file, Under General Tab, clicked the "Unblock" button.

seems like a Security Feature in Win2k3 and it says - "The file came from another computer and might be blocked to help protect this computer".

Some people got this problem fixed by:
going to add/remove windows components, then uninstalling the "Internet Explorer Enhanced Security component"

These issues seems to be strange and irritates sometimes, hence thought of sharing. May help someone.