Backendless SDK for Unity 2020.3 and up

One more thing you can check: What .NET profile are you using? You can check this in the Player Settings under Api Compatibility Level.

When I try to compile with .NET Standard 2.1 I get the same error as you have, but everything is fine when it is set to the .NET Framework (which I think the Backendless DLLs have been build with as well, which might explain this happening)

Yes, its true. Backendless.dll is created using .NET.Framework 4.7.1.

Just for a sanity check, I removed TestDataServices and BackendlessPlugin.cs, and I still get the error in 2020.3.26f1.

I switched to .NET 4.x and have the same issue.

I was able to get it to work in 2021.3, but I had to delete Newtonsoft.json because it was conflicting with another package that I can’t remove and doesn’t appear in the manifest or package manager. Removing Version Control did not fix the JSON issue for me this time. This issue does not happen in a blank project, so it may be included in another package that we are using.

It still does not work in 2020, but we have upgraded for our project, so this should no longer affect us.

Try updating Version Control to the latest version available. For me this solved the problem.

Hello, @Christopher_Ellis.

I just tried to build an android application. Here is the procedure that allowed me to do this:

  1. Create a project and import the latest version of unitypackage there.
  2. There is some conflict between .dll newtonsoft.json from Backendless and Version Control. To solve this problem, I updated the Version Control to the latest version (WindowPackage Manager find the Version Control there and click the Update button).
  3. A whole lot of errors appear that indicate that the system libraries are not available. This is because newer versions use netstandard 2.0 by default. To fix this, go to EditProject SettingsPlayer(Tab) → Scroll down and choose API Compatibility Level to .NET 4.x.
    After that, all errors disappear, set your App Id and API Key into BackendlessPlugin prefab.
  4. Then I switch platform to Android in this case for some reason API Level can switch back to netstandard 2.0 make sure you still have .NET 4.x.
  5. Congratulations, everything is ready. Then start the project.

By the way, we plan to add netstandard 2.0 support. At the moment, unfortunately, I cannot give you a clear timeline for when this will be done.

Best Regards, Nikita.