I had a problem a few weeks ago with a map, which I all of a sudden could not open. I was promtet with the "Failed to load the source schema (...). Would you like to select another schema using BizTalk Type Picker?". That was kind of wierd since the project still could compile. However I decided to just point to the same schema again, but the BizTalk Type picker was "empty". None of the referenced assemblies containing schemas where listed. I tried removing and adding references again and cleaning the solution - without any luck. 

I ended up giving up, and I created a new project and added the map and the needed references, and it worked. But now I am experiencing the same symptoms (same map and project), and I need to implement changes to the map. So now I am thinking that I need to get to the bottom of this, but I am lost for ideas.  

Seems there is some issue in the Visual Studio installed on your machine.

Did you try it on some other BizTalk  Server Installation?

FYI,Its a known issue with referencing projects in the solution. There is a hotfix for it too.

http://blogs.msdn.com/b/sanket/archive/2010/08/05/hotfix-for-assembly-reference-issues-with-biztalk-projects-in-visual-studio-2009.aspx

Hi

I also had similar kind of problem. Dont you worry your installation is OK but this problem is of referencing.

There are many solution to this problem :

1. Restart your visual studio

2. Check if there is any empty Folder in your solution.

3. Add reference of any project/.NET assembly you want and then assign its value to something else and then again assign its value to your desired value. Then build your solution, it will work.

Please mark as answer or helpful if this helped.

• Proposed as answer by Rahul_Madaan Tuesday, May 22, 2012 10:24 AM

David,

This Error usually happens when the Message in the Orchestration is not assigned to the corresponding Referenced Schemas, when you are getting these type of errors, just go to your orchestration and see wheather the messages is assigned to the Referenced Assembly (Schema).

These sort of errors, just vanishes when you restart the Solution / Just Rebuild the Referencing Applications.

Refer the Below thread which is similar to yours,

http://social.msdn.microsoft.com/Forums/en-US/biztalkgeneral/thread/2df94010-5755-4982-a02d-81f8feb51fda/

If the above happens oftenly (Lost the Assembly References ), just check the below thread and Hot fixes you may need.

http://social.msdn.microsoft.com/Forums/en-US/csharpide/thread/2a1e85b8-d57b-479d-b85b-4f407fdfc30e/

FIX: You experience various problems when you develop a BizTalk project that references another BizTalk project in Visual Studio on a computer that is running BizTalk Server 2009

I am not referencing projects, but I am dll's on my local drive. So therefore I can't se how that hotfix is relevant here. 

1. Restart your visual studio

Done.

2. Check if there is any empty Folder in your solution.

There where some empty folders within the solution. Deleting them did not have the desired effect though (I did restart VS after deleting the folders). 

3. Add reference of any project/.NET assembly you want and then assign its value to something else and then again assign its value to your desired value. Then build your solution, it will work.

I am not sure I completly understand what you are saying here. I have tried adding references to other assemblies containing xml schemas, and tried to use them from a newly created map in the same project. Same symtoms. The BizTalk Type Picker does not list any of the referenced assemblies, when I try to add a source/destination schema. 

I am not referencing projects, but I am dll's on my local drive. So therefore I can't se how that hotfix is relevant here. 

David,

You are referencing the Dll's In the Local Drive  of the Biztalk Local Projects I hope,

If not what sort of Dll's You are referencing ?

I am starting to think that this is not related to referencing issues. I have added a new xml schema, and a new map to the project. When I open the BizTalk Type Picker dialog to specify a source schema in the map, the current project is now listed. But the window closes (BizTalk Type Picker) when I attempt to expand the listed project to chose the new schema.

Hope this is not spam, but I have a similar problem.

If in my map project I reference the schema assembly, I get no schemas listed in the picker.  But if I reference the schema project instead, I can select the schema and the map looks fine -- yet after saving the map, it will not compile, getting the "Exception Caught: Cannot load source/destination schema .... Either the file/type does not exists, or ....." error.

I am using BTS 2009, and have the hotfixes installed.

Even i had the same issue in past.. i tried the below approach

  1) Closed Visual studio

   2) Delete the Bin and OBJ folders from solution folders

    3) Reopen the solution , and try to build the schema projectindependently

   4) and then references the the fresh Schema dll to Map Project ..

It solved issue for me .. hope it help..

Hi

I also had similar kind of problem. Dont you worry your installation is OK but this problem is of referencing.

There are many solution to this problem :

1. Restart your visual studio, Run as Adminsration

2. Check if there is any empty Folder in your solution.

3. Delete Schema dll file, and rebuild the Schema Project.

4. Add reference of any project/.NET assembly you want and then assign its value to something else and then again assign its value to your desired value. Then build your solution, it will work.

Please mark as answer or helpful if this helped.

Thank you! I came across a similar issue and your post helped me.

• Proposed as answer by G Vinay 15 hours 16 minutes ago

Thank you! I came across a similar issue and your post helped me.

• Proposed as answer by G Vinay Thursday, June 04, 2015 3:48 PM