ASP deployment error "failed to load type ..."

Today ProgramWhen deployed to the server and the first page is run, the error "failed to load type..." appears, but it is good on my machine.
After searching, I found a lot of countermeasures, but I found another situation-the ASP version should be changed to 2.0.

Last year, my program was written in vs2003. This year, my program used vs2005 to repeat it, delete all the contents in the directory on the server, and then use vs2005 to publish the program, then the above error occurs.
During the exclusion process, I found that vs2005 does not have global. asax, What is it used? I don't know, but the program can run normally. I think of the difference between vs2005 and vs2005, And I think of it again. net version problem, finally go to the server to change the directory version from 1.1 to 2.0.