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I'm building a C# (.NET 4.5) application that uses Newtonsoft.Json for various things. I'm trying to integrate Twitterizer, but it looks like it's trying to load a much older version of Newtonsoft.Json, causing a runtime exception.

I tried adding a redirect to my App.config, as follows:

<?xml version="1.0" encoding="utf-8" ?> <configuration> <startup> <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" /> </startup> <runtime> <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1"> <dependentAssembly> <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30AD4FE6B2A6AEED" culture="neutral"/> <bindingRedirect oldVersion="2.4.2.43046" newVersion="4.5.0.0"/> </dependentAssembly> </assemblyBinding> </runtime> </configuration>

Unfortunately, however, that has not solved the issue. Here's the exception after the redirect was added:

System.IO.FileLoadException: Could not load file or assembly 'Newtonsoft.Json, Version=4.5.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) File name: 'Newtonsoft.Json, Version=4.5.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' at Twitterizer.Core.TwitterCommand'1.ExecuteCommand() at Twitterizer.Core.CommandPerformer.PerformAction[T](ICommand'1 command) at Twitterizer.TwitterTimeline.UserTimeline(OAuthTokens tokens, UserTimelineOptions options) at (redacted).Workflow.GetMyTweets(Int32 count) in (redacted)\Workflow.cs:line 810 at (redacted).Workflow.Twitter() in (redacted)\Workflow.cs:line 787 at (redacted).Workflow.Execute(Int32 browser, Log WorkflowLog) in (redacted)\Workflow.cs:line 677

=== Pre-bind state information === LOG: DisplayName = Newtonsoft.Json, Version=4.5.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed (Fully-specified) LOG: Appbase = file:///(redacted)/bin/Release/ LOG: Initial PrivatePath = NULL Calling assembly : Twitterizer2, Version=2.4.2.43046, Culture=neutral, PublicKeyToken=69d1469eac671567. LOG: This bind starts in default load context. LOG: Using application configuration file: (redacted)\bin\Release\(redacted).vshost.exe.Config LOG: Using host configuration file: LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config. LOG: Post-policy reference: Newtonsoft.Json, Version=4.5.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed LOG: Attempting download of new URL file:///(redacted)/bin/Release/Newtonsoft.Json.DLL. WRN: Comparing the assembly name resulted in the mismatch: Major Version ERR: Failed to complete setup of assembly (hr = 0x80131040). Probing terminated.

Please note that, for a variety of reasons, I can't switch to a different Twitter library (i.e. Linq2Twitter et al are not an option), nor can I revert my JSON handling to the older library version used by Twitterizer.

What I need is to find a way to make this work without changing what libraries/versions I'm using.

Any ideas? Thanks for your help!

Kris Craig
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1 Answers1

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When you encounter such an issue, the only solution you can use is to import in your project the Newtonsoft .dll that you want to use (not the one for the library).

Then open the dll properties in your project references. There you will see a property called Aliases.

By changing the alias from global to my_alias, you will be able to use the other version of the library by referencing your alias.

In the code files where you want to use the aliased library you will have to use the extern keyword

extern alias my_alias;
// And then
using static my_alias::Newtonsoft.Json.Linq.JToken;
Linvi
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  • That's a great suggestion! Unfortunately, I'd already tried that and it didn't work. It might if I created a separate directory just for that older DLL or if I renamed it and loaded the assembly at runtime, but that'd be more cumbersome than just relenting and using the version bundled with the library. I ended-up just doing that, as it looks like the compatibility issues I feared turned out not to be as bad as I'd anticipated. Thanks! – Kris Craig Jun 15 '16 at 05:00
  • Though it didn't solve my specific use-case, I think your answer still deserves to be selected, as it probably would work if I had more time to make this exactly the way I'd want. – Kris Craig Jun 15 '16 at 05:02