Operation must use an updateable query

Microsoft OLE DB Provider for ODBC Drivers error '80004005'
[Microsoft][ODBC Microsoft Access Driver] Operation must use an updateable query.
This error usually happens when you try to insert data into or update data in an Access database. It means that you don't have sufficient permissions to write to the database.

If you are running the web server yourself then read the FAQ, Checking and Setting up the Correct Permissions on the Server.

If you are not running the server yourself you will need to contact your web space provider and ask them how to sort the problem out. You may need to use a special folder or they may have to setup a system DSN for you or change the permissions on the directory containing the database.

Cannot update. Database or object is read-only.

Microsoft OLE DB Provider for ODBC Drivers error '80004005'
[Microsoft][ODBC Microsoft Access Driver] Cannot update. Database or object is read-only.
This is the most common error that I'm asked about. This error usually happens when you try to insert data into or update data in an Access database. It means that you don't have sufficient permissions to write to the database.

If you are running the web server yourself then read the FAQ, Checking and Setting up the Correct Permissions on the Server.

If you are not running the server yourself you will need to contact your web space provider and ask them how to sort the problem out. You may need to use a special folder or they may have to setup a system DSN for you or change the permissions on the directory containing the database.

AjaxControlToolkit is undefined OR Sys' is undefined error in ASP.NET AJAX

adding this under httpHandlers:

<add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>

Turns out in the web.config nestled under <system.webServer> / <handlers>, I was missing this entry:

<add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />

When we get Error 'HTTP 502 Proxy Error' ?

We get this error when we execute ASP.NET Web pages in Visual Web Developer Web server, because the URL randomly select port number and proxy servers did not recognize the URL and return this error. To resolve this problem we have to change settings in Internet Explorer to bypass the proxy server for local addresses, so that the request is not sent to the proxy.

Operation must use an updateable query" error

Reason: Your database is in a folder where there is no write/change permission.
Resolution:
If using Windows 2000 - IIS5- the {Server}\ASPNET User Account must have Read, Write, and Change Control of the Folder where database resides
If using Windows 2003 - IIS6- the NETWORK SERVICE User Account must have Read, Write, and Change Control of the Folder where database residesGiving EVERYONE account full control will solve your problem too but Never do that as it will expose your system to external attacks within network.

Failed to load viewstate

cause
The exception occurs because the viewstate of the page must be restored to its previous state. This mean we need to re-load any control we loaded dynamically before the page load had being triggered.

Solution :
I was able to get it working by setting the PlaceHolder that I was dynamically adding the control to EnableViewState="False".
Set EnableViewStage=”false” in Page Directive

Deleting is not supported by data source 'SqlDataSource1' unless DeleteCommand is specified.

Solution:

if you need to pass parameters, then use the deleteparameters collection of the control.