Archive for the ‘.Net’ Category

Today a friend of mine started getting this error while he tried to deploy his solution to a server. This only started when ‘Precompiling during publishing’ option is selected.

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“Error 20 It is an error to use a section registered as allowDefinition=’MachineToApplication’ beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS.”

After having a look, I identified this was caused by a temporary copy of a Web.Config file. Earlier developer created a copy of the Web.Config and placed it inside a folder named Backup within the solution. This backup config file had authentication tag (<authentication>), which is a tag that can be only used in global Web.Config file or the Web.Config file in applications root. Due to the presence of authentication tag, compiler started complaining that there is a virtual directory not configured as a application in IIS.

The solution for my friend’s issue was to simply exclude the copy of the Web.Config file from project by right clicking the file. Then the project started deploying happily.

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While trying to setup and use the Code Plugin by Rich Hewlett I had trouble getting the plugin loaded into Live Writer. I did add the registry entry required as mentioned in the site, but still the plugin did not load.

Registry

Location – HKEY_CURRENT_USER\SOFTWARE\OpenLiveWriter\PluginAssemblies

Key – SyntaxHighlight_WordPressCom_OLWPlugIn

Value – C:\Users\Arjuna\AppData\Local\OpenLiveWriter\Plugins\SyntaxHighlight_WordPressCom_OLWPlugIn.dll

After a while I figured out that, when loading the plugin Live Writer encounters the following error.

"System.IO.FileLoadException: Could not load file or assembly ‘file:///C:\Users\Arjuna\AppData\Local\OpenLiveWriter\Plugins\SyntaxHighlight_WordPressCom_OLWPlugIn.dll’ or one of its dependencies. Operation is not supported. (Exception from HRESULT: 0x80131515)
File name: ‘file:///C:\Users\Arjuna\AppData\Local\OpenLiveWriter\Plugins\SyntaxHighlight_WordPressCom_OLWPlugIn.dll’ —> System.NotSupportedException: An attempt was made to load an assembly from a network location which would have caused the assembly to be sandboxed in previous versions of the .NET Framework. This release of the .NET Framework does not enable CAS policy by default, so this load may be dangerous. If this load is not intended to sandbox the assembly, please enable the loadFromRemoteSources switch. See http://go.microsoft.com/fwlink/?LinkId=155569 for more information.

This is due to a security feature of .Net Framework 4 or later. Before framework 4, if a DLL is downloaded (which is created in another computer), they used to run in full trust in the zone the assembly is running, but with frameworks 4 and later, downloaded DLLs will not run by default. To make them run, simply grant the DLL full access by going to file properties and selecting the Unblock checkbox in the security section as seen in the below image. This will apply to any plugin you download from internet. Also keep in mind to do this to DLLs you trust safe. Otherwise your computer will be unsafe.

image

To troubleshoot plugin and other errors you can refer to Open Live Writer log file located in C:\Users\Arjuna\AppData\Local\OpenLiveWriter\Open Live Writer.log.

As you may be knowing, you can use Windows PowerShell to change registry values. In this article I am going to do five things.

I have created few registry entries to use in this example as seen below. In real world you can use whatever entries in your registry. It is always advisable to backup your registry before changing it.

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1. Set a registry key value.

To set a value you need to use the “Set-ItemProperty” cmdlet as below.

Set-ItemProperty -Path "HKLM:\Software\Test\Live" -Name "TestValue2" –Value “TestData2”

Above command will put “TestData2” in the registry key “TestValue2” located in HKEY_LOCAL_MACHINE\Software\Test\Live.

2. Read a registry key value.

Reading from the registry can be done by using the cmdlet “Get-ItemProperty”.

Below command will get the value in the “TestValue1” key.

Get-ItemProperty -Path "HKLM:\Software\Test\Live" -Name "TestValue1"

3. Using variables in PowerShell.

Here I am going to read a registry key value and put it to another registry key. This can be done using a variable. First you need to read the value into a variable using the “Get-ItemProperty” cmdlet and that value can be saved using the “Set-ItemProperty” cmdlet.

  1. # Check for the existance of the registry key.
  2. IF (Get-ItemProperty -Path “HKLM:\Software\Test\Live” -Name “TestValue1” -ea 0)
  3. {
  4.     # Fetching the value from TestValue1.
  5.     $OldValue = Get-ItemProperty -Path “HKLM:\Software\Test\Live” -Name “TestValue1”
  6. }
  7. ELSE
  8. {
  9. # Inserting a blank, if the registry key is not present.
  10.     $OldValue = “”
  11. }
  12. # Printing the value in the variable.
  13. Write-Host $OldValue.TestValue1
  14. # Setting the value to TestValue2.
  15. Set-ItemProperty -Path “HKLM:\Software\Test\Live” -Name “TestValue2” -Value $OldValue.TestValue1

4. Working with registry keys with spaces.

In case your registry keys contain spaces, you need to use double quotes in your script as seen below.

  1. # Check for the existance of the registry key.
  2. IF (Get-ItemProperty -Path “HKLM:\Software\Test\Live” -Name “Test Value 1” -ea 0)
  3. {
  4.     # Fetching the value from Test Value 1.
  5.     $OldValue = Get-ItemProperty -Path “HKLM:\Software\Test\Live” -Name “Test Value 1”
  6. }
  7. ELSE
  8. {
  9.     # Inserting a blank, if the registry key is not present.
  10.     $OldValue = “”
  11. }
  12. # Printing the value in the variable.
  13. Write-Host $OldValue.“Test Value 1”
  14. # Setting the value to Test Value 2.
  15. Set-ItemProperty -Path “HKLM:\Software\Test\Live” -Name “Test Value 2” -Value $OldValue.“Test Value 1”

 

5. Saving PowerShell commands as scripts and running them.

Both above can be saved as a PowerShell script by saving it in a file with the extension ps1. For example I did save it as “ChangeReg.ps1” in my C drive inside the folder “new”. Then the script can be run by browsing to the folder and using the command “.\ChangeReg.ps1”.

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After the script is run my registry keys looked like this.

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In case you need to retrieve values from other registry hives (locations), following table may be helpful.

 

Registry Hive

Abbreviation

1. HKEY_CLASSES_ROOT HKCR
2. HKEY_CURRENT-USER HKCU
3. HKEY_LOCAL_MACHINE HKLM
4. HKEY_USERS HKU
5. HKEY_CURRENT_CONFIG HKCC

 

In case you need to read more on “Get-ItemProperty” and “Set-ItemProperty”, use the links to visit official documentation from Microsoft TechNet.

Request Filtering

I recently got this error in one of my applications. When troubleshooting, I found my application is configured to have the default value of 30000000 Bytes for the content length, which was not sufficient for me in some of the file uploading functionalities.

Simply adding / increasing the number in the configuration file corrected this error.

Request Content Length in Bytes.

Default Value – 30000000 Bytes (~28MB)

Maximum Value – 4284229877 Bytes (3.99GB)

  1. <system.webServer>
  2.   <security>
  3.     <requestFiltering>
  4.       <requestLimits maxAllowedContentLength=100000000></requestLimits>
  5.     </requestFiltering>
  6.   </security>
  7.   …
  8. </system.webServer>

 

To obtain more information read this article.

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Sometime back I started getting this error in all the forms in which AJAX tools were used. The thing worried me most is that there were no changes made to the project source code. Later a friend of mine found that it is happening because of the wrong AjaxControlToolkit.

As I feel this dll swap happens when a control is dragged from the Visual Studio toolbox because the toolbox is referenced to a newer version of the toolkit than the project was using.

If you are also getting this error simply delete all the AJAX related files and folders in your projects’ bin directory. Once you are done there should not be any folders such as ar, cs, de, etc. Also remove the AjaxControlToolkit.dll. Then copy the version of the toolkit dll your project was using earlier to the Bin directory. Now clean and build your project to see the error disappear.

If you are still getting the error after correctly doing all this you might be getting the error due to another reason causing the same error. Since there are many reasons for this same error you better check the internet for other reasons to find out the exact reason causing the error for you.

Recently I encountered a positioning error in AJAX calendar extender. When I use the calendar extender inside of other container controls the popup calendar started appearing few inches above the button. You will be able to get an idea of the problem by the following image.

image

Since I couldn’t get it fixed by changing the properties I thought to find a solution for this.

One way to correct this is by applying a CSS style sheet to change the calendar positioning manually. I found this method while searching the web. This way since you need to enter the location of the calendar you need to try several times to get the correct positioning. If you are using this method simply place the following CSS style in your page and apply the style as shown. Remember you need to change the value to suit your form.

  1. <style type="text/css">
  2.     .fromDtPos
  3.     {
  4.         left: 245px !important;
  5.     }
  6. </style>

Apply the style to your calendar extender.

  1. <cc2:calendarextender id="calExpiry" runat="server" targetcontrolid="txtExpiry"
  2.     format="dd MMM yyyy" popupbuttonid="imgExpiry" enabled="True" cssclass="ajax__calendar fromDtPos">
  3. </cc2:calendarextender>

My preferred way to do this is by using the JavaScript that I wrote below. Since you do not need to enter the position manually this will be easier. Also this code will work irrespective of the number of parent containers it is having above of the control.

Insert the below JavaScript into your page.

  1. <script type="text/javascript" language="javascript">
  2.     function showCalendar(sender, args) {
  3.         var processingControl = $get(sender._button.id); // Getting the control which triggered the calendar.
  4.         sender._popupDiv.parentElement.style.top = processingControl.offsetTop + processingControl.height + ‘px’;
  5.         sender._popupDiv.parentElement.style.left = processingControl.offsetLeft + ‘px’;
  6.  
  7.         var positionTop = processingControl.height + processingControl.offsetTop;
  8.         var positionLeft = processingControl.offsetLeft;
  9.         var processingParent;
  10.         var continueLoop = false;
  11.  
  12.         do {
  13.             // If the control has parents continue loop.
  14.             if (processingControl.offsetParent != null) {
  15.                 processingParent = processingControl.offsetParent;
  16.                 positionTop += processingParent.offsetTop;
  17.                 positionLeft += processingParent.offsetLeft;
  18.                 processingControl = processingParent;
  19.                 continueLoop = true;
  20.             }
  21.             else {
  22.                 continueLoop = false;
  23.             }
  24.         } while (continueLoop);
  25.  
  26.         sender._popupDiv.parentElement.style.top = positionTop + ‘px’;
  27.         sender._popupDiv.parentElement.style.left = positionLeft + ‘px’;
  28.     }
  29. </script>

Then call the function showCalendar on onClientShown event of the calendar extender as seen below.

  1. <cc2:calendarextender id="calExpiry" runat="server" targetcontrolid="txtExpiry"
  2.     format="dd MMM yyyy" popupbuttonid="imgExpiry" enabled="True" onclientshown="showCalendar">
  3. </cc2:calendarextender>

Both of the above methods will correct the appearance of the popup calendar of the AJAX Calendar Extender as seen below.

image

Recently in one of my machines I got the above HTTP error when running an application hosted on IIS 7. The detailed error was as below.

IIS Error

“This configuration section cannot be used at this path. This happens when the section is locked at a parent level. Locking is either by default (overrideModeDefault="Deny"), or set explicitly by a location tag with overrideMode="Deny" or the legacy allowOverride="false".”

After doing some troubleshooting I was managed to get this error fixed by reinstalling ASP.Net by running the aspnet_regiis –ir command.

For more information on running the command please refer to my old article Unable to start debugging on the web server.