ASP。Net -新版本的代码是否仍然使用以前的程序集?

Yesterday, after about two years we re-deployed our application. Code hasn't changed, but the constituent project structure has been re-organised into smaller projects. It all seemed to be fine until today (at 5.29pm) one of our users pointed out an issue. From the nature of the error encountered it is clear that the newly deployed app is Yesterday, after about two years we re-deployed