RegisterForEventValidation can only be called during Render() ASP.Net

The prefect solution is use EnableEventValidation="false" in Page tag.

<%@ Page Title="" Language="C#" MasterPageFile="MasterPage.master" AutoEventWireup="true" EnableEventValidation="false"
    CodeFile="checkout.aspx.cs" Inherits="LD.checkout" %> 

Click Here to see in more detail

Related Alrticles

• Download run-classic-asp-pages-with-iis7-iis6
• Download add-meta-title-meta-description-meta-keywords-dynamically-in-header-Asp-Net
• Download introduction
• Download add-google-ecommerse-code-in-Asp-Net
• Download how-get-dataview-values-after-rowfilter-in-Asp-Net
• Download read-data-from-xml-file-bind-dataset-and-row-filter-on-dataview
• Download the-controls-collection-cannot-be-modified-because-the-control-contains-code-blocks
• Download how-to-send-email-with-multiple-attachments-in-Asp-Net
• Download how-get-image-height-width-in-Asp-Net
• Download webform_dopostbackwithoptions-submit-button-does-not-cause-postback
• Download how-get-yesterdays-date-in-Asp-Net
• Download http-error-500-22-internal-server-error
• Download how-to-work-with-timezone-utc-ist-est-in-Asp-Net
• Download parse-float-with-two-decimals
• Download send-email-in-classic-asp
• Download how-to-make-connection-string-for-sql-or-ms-access-in-classic-asp
• Download how-to-import-gmail-contacts-in-Asp-Net
• Download itemdatabound-and-item-command-in-Asp-Net
• Download get-the-all-files-with-their-name-size-from-a-folder-Asp-Net
• Download point-inside-the-polygon-using-latitude-longitude-Asp-Net
• Download make-polygon-geofence-in-Asp-Net-html
• Download fill-dataset-by-data-adapter-using-stored-procedure-Asp-Net
• Download delete-files-in-Asp-Net
• Download Asp-Net-create-google-compliant-dynamic-xml-sitemap-in-Asp-Net
• Download how-to-select-all-checkbox-inside-a-gridview-datagrid-in-Asp-Net-javascript
• Download find-controls-of-usercontrols-in-aspx-cs-file-in-Asp-Net
• Download get-page-title-and-assign-that-title-to-master-page-Asp-Net
• Download how-to-prevent-sql-injection-in-Asp-Net-or-asp-or-php-website
• Download get-the-page-content-datagrid-datalist-gridview-content-and-send-in-email-Asp-Net
• Download how-to-pass-parameters-to-sql-server-procedure-in-Asp-Net
• Download how-to-send-an-email-or-perform-other-operation-from-aspx-page-without-cs-or-vb-file-Asp-Net
• Download to-send-email-using-gmail-account-Asp-Net
• Download how-to-create-a-thread-in-Asp-Net
• Download create-datatable-dynamically-in-Asp-Net
• Download how-add-the-rows-dynamically-in-datatable-Asp-Net
• Download how-to-get-the-date-time-of-client-pc-in-Asp-Net
• Download how-to-auto-refresh-a-web-page-every-two-minutes
• Download export-datagrid-gridview-to-excel-csv-format-on-the-fly-in-Asp-Net
• Download could-not-load-file-or-assembly-app-web-version0-0-0-0
• Download export-to-excel-download-popup-window-not-working-in-Asp-Net
• Download displaying-the-files-from-a-directory-using-a-datagrid-Asp-Net
• Download remove-html-tags-from-a-string-in-Asp-Net
• Download read-write-or-add-update-html-or-text-files-in-Asp-Net
• Download format-phone-numbers-in-us-united-states-phone-number-format-in-Asp-Net
• Download registerforeventvalidation-can-only-be-called-during-render-Asp-Net
• Download read-html-file-in-Asp-Net
• Download read-html-file-in-Asp-Net-vb
• Download registerforeventvalidation-can-only-be-called-during-render
• Download could-not-find-any-resources-appropriate-for-the-specified-culture-or-the-neutral-culture-make-sure-ajaxcontroltoolkit-properties
• Download stubhub-com-apis-implementation-in-Asp-Net
• Download writing-alphabets-loop-from-a-to-z-in-Asp-Net
• Download embeded-font-files-woff-not-working-in-window-shared-hosting
• Download uncaught-exception-error-raising-upload-complete-event-and-start-new-uploadcancel
• Download get-files-from-directory-or-folder-in-Asp-Net
• Download add-a-favicon-in-a-website-pages
• Download the-request-filtering-module-is-configured-to-deny-a-request-that-exceeds-the-request-content-length
• Download change-string-to-proper-case-in-an-Asp-Net-using-C-Sharp
• Download how-to-call-javascript-function-after-an-updatepanel-asychronous-request-to-Asp-Net-page
• Download use-of-unassigned-local-variable-string-or-string-builder-Asp-Net-C-Sharp
• Download webforms-unobtrusivevalidationmode-requires-a-scriptresourcemapping-for-jquery
• Download read-xml-file-using-xmlreader-in-C-Sharp
• Download limitshow-number-of-characters-remaining-in-multiline-textbox-or-textarea-jsjavascript
• Download write-xml-file-using-xmlreader-in-C-Sharp
• Download wrapping-text-around-an-image-with-indentation-and-justify-html-css-Asp-Net
• Download make-excehsheet-from-html-in-Asp-Net-C-Sharp
• Download how-can-i-show-currency-with-negative-instead-of-parentheis-in-asp-net-gridview-datagrid