The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Question

After signing the third parties assemblies and adding them to GAC I am getting the below error: also the Assembly Binder Log Entry shows this error

It says mismatch

Answer 1

From my experience, this happens, usually once you've published your app and when you have different versions of nuget packages in play. If this happens to be your situation as well, the best way I've found to fix it is to right-click the solution (not the individual projects) and choose "Manage Nuget Packages". Then, locate the offending assembly in the installed packages. You'll probably see it listed multiple times. Click "Manage" on each of the older versions of the package and uncheck all your projects. Once only the latest version of the package remains in the list. Click "Manage" on this one and recheck any projects that need the package. This will essentially upgrade them all to use the same version of the package and should resolve your mismatch error.