build error
 

hi,
When i try to compile a solution file i am receiving the following error How can i solve it.



Building project step 'Make VS.NET'...
Item has already been added. Key in dictionary: '3BB40790-AFF9-48A4-A97C-38B9ED99EF1C' Key being added: '3BB40790-AFF9-48A4-A97C-38B9ED99EF1C'
Step 'Make VS.NET' failed
Build ended.