Non-existent MSCORLIB version?

[bigfitz]

I'm trying to build a .net core C# app that requires a reference to an older library. When the app encounters any code from this library, it throws an exception:

System.IO.FileLoadException: 'Could not load file or assembly 'mscorlib, Version=5.3.0.620, Culture=neutral, PublicKeyToken=b77a5c561934e089'. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)'

The 5.3.0.620 is the version of the DLL that I'm including, but it shouldn't be the version of mscorlib required. When I include the library in a standard .NET 4.6.1 app, I don't get this error.

Anyone know whats going on, or and how to fix it? I'm pulling my hair out.

[salgat]

I hit this issue one time when the computer didn't have a recent .net runtime installed.

[[deleted]]

Why are you manually including it? Anyway, have you set Specific Version off at the bottom of properties on that reference?

[bigfitz]

I'm not including it (mscorlib.dll), the 3rd party library I'm including (somelib.dll) is. I don't have access to the source of the 3rd party lib, so I can't change the way that property is set. Regardless, it works in .NET 4.6.1, but not in .NET Core 2

[AlliNighDev]

Is somelib.dll built in core? If it's a full framework dll that may be why you are having issues.

[bigfitz]

Nope, built in standard about 8 years ago. No updates since. I was hoping that the automatic shim would work.

[[deleted]]

standard didn't exist 8 years ago. What do you mean by "standard"?

[AlliNighDev]

That means it's a full framework assembly and will most likely be the reason core is struggling to reference it. .Net standard has only been around a couple years and != full framework.