ASP.Net error - type is not compatible with the type of control

asp.net .net vb.net visual-studio-2012 runatserver

17,776

Solution 1

OK,

So after trying a lot of stuff that didnt work i found a solution, i dont like this solution but it works,

I went to the page.designer.vb file, and then looked for the 'html' and 'Head1' properties that were generated there,

In there i replaced their types to System.Web.UI.HtmlControls.HtmlGenericControl

Afterwards, it worked.

Weird bug, nothing else (including the "hot fixes" that are mentioned in other posts helped.

Hope this would help some one out there .

Solution 2

Somehow the designer file and the markup file get out of sync, even if the types appear to match.

I changed the ID attribute of the problematic control, saved, and rebuilt in the markup file. I then changed it back to the original ID, saved, and rebuilt.

Problem goes away!

17,776

Author by

Matan L

Updated on June 14, 2022

Comments

Matan L almost 2 years
I have a web site i created using VS2012 web edition,

Running a VB.net asp web site,

In the VS2012 debug/release mode it compiles and everything works good, When i upload it to a server (Windows server 2008 R2) I get the following error:
```
The base class includes the field 'html', but its type (System.Web.UI.HtmlControls.HtmlElement) is not compatible with the type of control (System.Web.UI.HtmlControls.HtmlGenericControl).


Line 2:  
Line 3:  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
Line 4:  <html id="html" xmlns="http://www.w3.org/1999/xhtml" dir="ltr" runat="server">
Line 5:  <head id="Head1" runat="server">
Line 6:    <title></title>
```
I looked a bit on the web and found this : VS 2010: Value of type 'System.Web.UI.HtmlControls.HtmlGenericControl' cannot be converted to 'System.Web.UI.HtmlControls.HtmlTableRow'

Installed it but no help,

The site i created was re-created from another vb.net project so i used a web.config with from the old one, maybe it has something to do with it, i have no "assembly" properties it this XML.

Other pages that are not related to that master page (that html tag is running on a master page...) work's fine.
IvanH over 10 years

Did you managed to find why behavior is different on server and in VS?
Edward almost 9 years

FYI: I just had to do this as well in a C# app. Thank you - saved me some serious time!
NetworkMonkey almost 6 years

What I did to fix this is right click the solution>clean, then I deleted the bin folders under my projects and rebuilt the solution. From my understanding you shouldn't manually edit the *designer.cs files so I wanted to add this here. I know this is an old thread but since I ended up here someone else might too.
Niklas about 4 years

happened to me because i was using 2 different IDEs at the same time. all i did was closed the other one and opened the solution with visual studio and saved the aspx design file. it auto generated the designer.cs and it all went fine after that.