Unknown server tag error for a custom control RRS feed

  • Question

  • User-1600963911 posted
    I have looked a lot other posts related to this error and not been able to find explanation to my situation.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>When I drop the custom control I made from Toolbox to a page, two lines of code are created:<o:p></o:p><%@ Register assembly="ClinicalServerControls" namespace="ClinicalServerControls" tagprefix="ClinicalServerControls" %>


    <o:p></o:p><ClinicalServerControls:ClinicalDropDownList ID="ClinicalDropDownList1" runat="server"> </ClinicalServerControls:ClinicalDropDownList>


    <o:p></o:p>When building the Web site, I get the following error:


    <o:p></o:p>Unknown server tag 'ClinicalServerControls:ClinicalDropDownList'


    <o:p></o:p>The most bizarre thing is that the custom control, used in exactly the same way,  works perfectly on pages of another similar Web site in the same solution. <o:p></o:p>Any tip will be greatly appreciated.<o:p></o:p>


    Wednesday, July 9, 2008 7:44 PM


All replies

  • User-1600963911 posted


    I found the custom control has the problem on a Web site located on a network drive.

     As I mentioned in my previous message,  the custom control works on Web site A, but has the problem on Web site B.  BTW, I am using VS Standard.  Out of curiosity, I created two brand new Web sites, one on the network drive and the other on the local drive.  Each site simply has only one page.  Guess what?  The custom control works perfectly the local drive Web site, but has the same problem on the network drive Web site.

    I am looking into the security.  Any hint will be greatly appreciated.


    Thursday, July 10, 2008 9:25 AM
  • User-1600963911 posted

    Hallelujah!  I figured out.

    I got a hint from the following post:


    I followed the following MSDN instructions


    Everything is ticking now.

    • Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM
    Thursday, July 10, 2008 10:03 AM