visual studio | Moving the Curve

This morning I needed to work on a long-standing ASP.NET web application project. I haven’t had to run it locally for quite a while. I updated my source from TFS, cleaned and built the solution, and started the project in debug mode. After logging in, I went to a page, and was suddenly staring at an unexpected and confusing exception:

The base class includes the field 'ScriptManager1', 
but its type (System.Web.UI.ScriptManager) 
is not compatible with the type of control 
(System.Web.UI.ScriptManager).

I put aside the surprise that a type was not compatible with itself, and checked the source control history. The specific page hadn’t been changed since the last time I’d tried it. I know the project is under active development, including a recent deployment of the latest version at the client site, so I had ever reason to believe the build should work.

Before sending a panicked email to my team, I did a quick Google search. I found a couple links of similar people with this problem in VS2008, but I’m still running VS2005.

I realized, however, that I had installed Framework versions 3.0 and 3.5 since I had last had to work on this project. I went to the project references, and checked that for System.Web.Extensions, and noticed that “Specific Reference” was set to false. I set this to true, rebuilt the project, and started the debugger again.

This time, success! The page displayed as expected.

What problems have you encountered from having multiple .NET Frameworks installed?

A problem I just faced: I was trying to use Visual Studio 2005 on my Windows XP box to connect to a Team Foundation Server (TFS) via VPN to check out some source code. I would attempt to connect to the server, and would then receive the error message that USERA did not have permission to access the server. The problem was, I didn’t want to connect to the server as USERA, but rather as USERB. It would never give me a login prompt, however, just repeat the message that I could not connect as USERA.

I was VPN’ed into the system via Cisco, and thus hadn’t yet given any Windows network credentials, so I was puzzled from where it was getting the opinion I wanted to be USERA.

After trying to delete the server multiple times and add it back in, it finally occurred to me that I had connected to that server via Network Places. I opened the Network Places window, but the server didn’t show up there.

Finally I started hunting through control panels. I hit upon User Accounts, opened that, and clicked the Advanced tab. I clicked the Manage Passwords button, and there under Stored User Names and Passwords, wouldn’t you know it, an entry for the server in question. I selected it, clicked Remove, and Closed out of the User Accounts Control Panel.

I tried to connect to TFS through File > Open from Source Control, selected my server, and got the login box I expected instead of an error message. Progress!

Moral of the story: be very careful when you select the option for Windows to remember your login credentials. It may have unintended consequences. And if you let your OS (or any application/system) cache your login information, be sure you know where to go to change it in case you need to.

Moving the Curve

Technology, code, and thoughts by Stevi Deter

Category Archives: visual studio

Picking the right .NET Framework Version with Specific Reference