Is your DNN Upgrade stuck with ‘Could not load file or assembly ‘Newtonsoft.Json’ Error?

This error mainly occurs when the DNN website has an incorrect version of the Newtonsoft.Json package in its configuration.

At Bobcares, we often get requests to fix DNN errors, as a part of our Server Management Services.

Today, let’s see how our Support Engineers fix the error for our customers.

When does the Newtonsoft.Json Error occur?

It’s now time to see more details of the Newtonsoft.Json Error.

DNN websites hold a web.config file that allows customization of a specific directory.

Newtonsoft.Json is a package used to implement the core services of the .NET framework. It helps in converting between .NET objects and JSON.

Mainly JSON shows this kind of error when there is a difference in the version specified on the web.config file and its original version of the JSON package.

Other reasons for the error are when the code is missing in the web.config file and the outdated version.

How we fix ‘Could not load file or assembly Newtonsoft.Json’ Error?

Let’s now check the main reasons for the ‘Could not load file or assembly Newtonsoft.Json‘ Error and see how our Support Engineers fix it for our customers.

1.Difference in Version

While upgrading the DNN site, we may encounter the below error.

This occurs after we copy the new DNN upgrade files and call the upgrade path in the browser. In this case, we follow the below steps to fix the error. Also, note that we don’t restore the site.

1. Initially, we go to the bin folder in the website folder and select the Newtonsoft.Json.dll file.

2. Then right-click the Newtonsoft.Json.dll file and Click the Properties.

3. There we see the file version of the Newtonsoft.Json.dll file and we noted the version.

4. Then we navigate to the web.config file and find the version of Newtonsoft.Json.

5. Then we compare the version of Newtonsoft.Json in web.config and with the file version of the .dll file.

6. After that, we correct the file version in the web.config file and then again call the upgrade path.

This fixes the error. We fix the error by making the version of Newtonsoft.Json on web.config file and version of Newtonsoft.Json.dll file to the same.

2.Missing Code in Web.config file

Sometimes the error occurs when the code is missing in the web.config file. We fix it by adding the below code in the web.config file.

Initially, we check the installed Newtonsoft.Json version. In a recent error, on checking, we found that Newtonsoft.Json 11.0.0.0 version was installed on the server.

So we manually added the following code inside the web.config file.

<dependentAssembly>
<assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-11.0.0.0" newVersion="11.0.0.0" />
</dependentAssembly>

That made the website working again.

3. Outdated Newtonsoft.Json Package

If the Newtonsoft.Json Package is outdated then the ‘Could not load file or assembly Newtonsoft.Json’ error may appear.

So we check the version of the Newtonsoft.Json Package and update it to the latest one.

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Conclusion

In short, we have discussed the main reasons of ‘Could not load file or assembly Newtonsoft.Json’ Error and saw how our Support Engineers fix this error for our customers.