Solution for “Invalid URL value. A URL field contains invalid data. Please check the value and try again”

If you try to update field of type SPUrlField in SPListItem, you may encounter “Invalid URL value. A URL field contains invalid data. Please check the value and try again” error. This error can occur due to several reasons. I found a good description in a Microsoft SharePoint forums by Somak Bhattacharyya . I found it quite useful and  hope it will help you to fix this issue:

1. The URL that you are creating doesn’t exceed 255 characters. This is because the Hyperlink type column in SharePoint does not accept more than 255 characters as an URL. This is what had happened personally to me . Had a pretty tough time figuring it out myself.
2. Check that your URL is well-formed. To check this, try to browse the URL, that you are generating, in IE and see whether it points to your desired target. Just Copy paste the URL generated to the Address bar of IE and press enter. Ideally this should open the page you are trying to link to. If it is not then you instantly know that what you are generating is wrong. Correct it!
   NB: You may get the URL generated runtime from inside your Code by logging it into the Event Log or just by redirecting it to a text file or invoking IE by passing the URL generated as a parameter.
3. If you are directly assigning the value to the column like:
   Item[“”] = “,”, then check that you are not missing the after the comma.
4. The best possible way to do it I feel is in this way:

   SPFieldUrlValue yourURL = new SPFieldUrlValue();
   yourURL.Url = "";     // For example: www.microsoft.com.
   yourURL.Url = yourURL.Url.Replace(" ", "%20");    // This is however optional.
   yourURL.Description = ""; // eg:Microsoft.