How to solve the error: "type or namespace system.data does not exist" in Mac OS X

To solve the error: “type or namespace system.data does not exist” using Window, we can copy and paste the .dll file of System.Data into the Assets\Plugins folder. However as for the Mac OS X version, how does it work to solve the error that the system.data does not exist?

System.Data is not part of the default distribution, you need to put it in your plugin folder. But you need to use the mono versions provided with unity

Win:
C:\Program Files (x86)\Unity\Editor\Data\Mono\lib\mono\2.0

Mac:
/Applications/Unity/Unity.app/Contents/Frameworks/Mono/lib/mono/2.0

maybe, only you need save your project or is the .net configuration, use the .NET 2.0 (not subset) and will connect. I was able to transmit data, but not to receive. Config is into Edit>ProjectSettings>Player>ApiCompatibilityLevel.

You are using the wrong code-profile in your project. Go to “Player Settings” and set your API compatibility level to “2.0” instead of “2.0 Subset”.

The documentation contains the list of available classes for each subset.

The file size with the full API is only marginally larger than the ‘subset’ API. For standalone builds it is not even worth worrying about, as adding a single texture has more impact on the size than that setting.