(Plese.Help Me)Plugin 'System.Data.dll' is used from several locations:

i am using mysql and unity3d.

running is no problem.

but when i build project , i got a problem.

[
Plugin ‘System.Data.dll’ is used from several locations:
Assets/Plugins/System.Data.dll would be copied to /System.Data.dll
Assets/System.Data.dll would be copied to /System.Data.dll
Please fix plugin settings and try again.

UnityEditor.Modules.DefaultPluginImporterExtension:CheckFileCollisions(String)
UnityEditorInternal.PluginsHelper:CheckFileCollisions(BuildTarget) (at C:/buildslave/unity/build/Editor/Mono/Plugins/PluginsHelper.cs:25)
UnityEditor.HostView:OnGUI()

Plugins colliding with each other.

]

Asset\MySql.Data.dll

Asset\System.Data.dll

Asset\Plugins\System.Data.dll

Asset\Plugins\System.Drawing.dll

i want build and run .

Thank you.

You have multiple versions of the dll that are both set to be used for the same platform or cpu. Unity 5 introduced new plugin settings so that you can compile different versions of the same dll, but you need to specify which platform or cpu each version is for. Checkout this link for more info.

To add to LessThanEpics response: My collision was with Exiflib.dll. When I did a dir/s on my project folder, I found the file in three locations that Unity would search: under \Library, under Assets\Library, and under Assets\Plugin. Unity is trying to protect you with this message, as building with the wrong DLL can be the source of maddening errors.

There are often legitimate reasons for having more than one, so the PluginInspector is provided so you can instruct the Builder when each should be used. But in my case it wasn’t necessary. I whacked all but one, and then Unity was able to build again.

Note that after the build, the DLL was again in multiple areas, but in places like PlayerDataCache, which aren’t search by the Builder.

delete extra system.data.dll file