Could not load file or assembly 'System.Buffers, Version=4.0.2.0...'

Question

I'm getting the following exception when trying to call GetDatabase method of the MongoClient class after adding a new configuration using VS config. manager:

Could not load file or assembly 'System.Buffers, Version=4.0.2.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

I installed the latest System.Buffer nuget package v4.5.1, created dependentAssembly in my app.config and Reference in my .csproj file, but I still have the same issue. For some reason it tries to reference System.Buffer with v4.0.2. Has anyone had a similar error and how did you solve it?

Answer 1

The easiest way is to use Nuget package manager, downgrade system.buffers to any lower version, and then upgrade it to the latest again.

Answer 2

In my case, I had to add the assembly reference in the web.config that was already published in the Azure App Service, inside the <configuration></configuration> tag:

<runtime>
  <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
    <dependentAssembly>
      <assemblyIdentity name="System.Buffers" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
      <bindingRedirect oldVersion="0.0.0.0-4.0.3.0" newVersion="4.0.3.0" />
    </dependentAssembly>
  </assemblyBinding>
</runtime>

Answer 3

Could not load file or assembly 'System.Buffers, Version=4.0.2.0…'

Solution

1) use CMD(run as Administrator ) and type

 cd xxxx(xxxx\packages\System.Buffers.4.5.1\lib\netstandard2.0))

run

gacutil /i System.Buffers.dll

Then, when you finish it, please run update-package -reinstall under package manager console to reinstall the package.

2) you can try to change Version=4.0.2.0 to Version=4.0.3.0 in csproj file.

Besides, there is a similar issue you can refer to.