Migrate old VB.NET project from VS2013 to VS2017

Question

I have a huge enterprise asp.net application that perfectly builds and runs on servers. We've been using Visual Studio 2013 in our workflow. Now we want to migrate to newer IDEs. But if I build this application in Visual Studio 2017 I'll get this error.

Error BC40004 sub 'PreInit' conflicts with event 'PreInit' in the base class 'Page' and should be declared 'Shadows'.

I think it's a problem with VB compiler version (again vs2013 builds project). Do you have any idea how to fix this?

My solution contains 40+ projects. The main project is asp.net webforms app written in VB.net. Other projects are services and code libraries written in C#.

I tried to specify VB.net version in .vdproj manually. But it didn't solve my problem.

edit: Fine. Thank you all for your responses. I got that problem is about code and that visual studio analyzer has changed a lot in the last few years. I'll try to find out the reasons why this code have been working without exceptions.

Answer 1

BC40004是警告，除非您在选项卡编译下的项目属性上将“ Treat warnings as errors设置，否则不应阻止您编译解决方案。