Why do I receive the error 'The string '[XXXXXX]' is not a valid AllXsd value' when my web form loads?

Development Visual Studio Web Forms
1

Issue

You are receiving the error The string '[XXXXXX]' is not a valid AllXsd value when the web form loads.

Reason

The web control that receives the string value [XXXXXX] has a WorkflowGen field data type specified that is not of type ‘String’.

For example, the following control for a request date has the the FieldDataType extended attribute set to DateTime:

<asp:Label ID="REQUEST_DATE" runat="server" FieldDataType="DateTime" FieldFormat="{0:d}" ></asp:Label>

If the action IN parameter passes a text string or anything that is not in a valid date format, WorkflowGen will cause a compilation error when the form is loaded.

You will receive a similar error if the FieldDataType extended attribute is Numeric or Currency.