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Won't Fix

Votes

1

Found in

2017.1.0b1

Issue ID

905072

Regression

Yes

Error appears when project is opened with a newer version, and script with error is deleted, and a new script is created

Scripting

-

To reproduce:
1. Open attached project with Unity 2017.1.0b4
2. Delete "NewBehaviourScript.cs"
3. Create a new C# script.

To reproduce from scratch:
1. Create new project with Unity 2017.1.0b1 (or older)
2. Create a new C# Script.
3. Make sure C# script has an error.
4. Close Unity.
5. Open Same project with 2017.1.0b2 (or newer)
6. Delete that script.
7. Create a new C# script.

Expected result: No errors.
Actual result: An error appears.

Reproducible:
5.5.0a6 - 5.5.3p2 (error appears if previous project was made with 5.4.0b14 or older)
5.6.0a2 - 5.6.0p3 (error appears if previous project was made with 5.4.0b14 or older)
2017.1.0a2, 2017.1.0b4 (with any previous version)
2017.2.1p1
2017.3.2f1
2017.4.9f1
2018.1.0b6

Did not reproduce:
5.3.7p1
5.4.5p1
2018.1.9f1
2018.2.2f1
2018.3.0a8

Error message
:error CS1704: An assembly with the same name `UnityEngine.UI' has already been imported. Consider removing one of the references or sign the assembly
E:/Unity/Unity 2017.1.0b2/Editor/Data/UnityExtensions/Unity/GUISystem/UnityEngine.UI.dll (Location of the symbol related to previous error)
E:/Unity/Unity 2017.1.0b2/Editor/Data/UnityExtensions/Unity/GUISystem/Standalone/UnityEngine.UI.dll (Location of the symbol related to previous error)
error CS1704: An assembly with the same name `UnityEngine.Networking' has already been imported. Consider removing one of the references or sign the assembly
E:/Unity/Unity 2017.1.0b2/Editor/Data/UnityExtensions/Unity/Networking/UnityEngine.Networking.dll (Location of the symbol related to previous error)
E:/Unity/Unity 2017.1.0b2/Editor/Data/UnityExtensions/Unity/Networking/Standalone/UnityEngine.Networking.dll (Location of the symbol related to previous error)
error CS1703: An assembly `nunit.framework' with the same identity has already been imported. Consider removing one of the references
E:/Unity/Unity 2017.1.0b2/Editor/Data/UnityExtensions/Unity/TestRunner/nunit.framework.dll (Location of the symbol related to previous error)
E:/Unity/Unity 2017.1.0b2/Editor/Data/UnityExtensions/Unity/TestRunner/standalone/nunit.framework.dll (Location of the symbol related to previous error)
error CS1704: An assembly with the same name `UnityEngine.Timeline' has already been imported. Consider removing one of the references or sign the assembly
E:/Unity/Unity 2017.1.0b2/Editor/Data/UnityExtensions/Unity/Timeline/RuntimeEditor/UnityEngine.Timeline.dll (Location of the symbol related to previous error)
E:/Unity/Unity 2017.1.0b2/Editor/Data/UnityExtensions/Unity/Timeline/Runtime/UnityEngine.Timeline.dll (Location of the symbol related to previous error)
error CS1704: An assembly with the same name `UnityEngine.HoloLens' has already been imported. Consider removing one of the references or sign the assembly
E:/Unity/Unity 2017.1.0b2/Editor/Data/UnityExtensions/Unity/UnityHoloLens/Runtime/UnityEngine.HoloLens.dll (Location of the symbol related to previous error)
E:/Unity/Unity 2017.1.0b2/Editor/Data/UnityExtensions/Unity/UnityHoloLens/RuntimeEditor/UnityEngine.HoloLens.dll (Location of the symbol related to previous error)

Compilation failed: 5 error(s), 0 warnings

  1. Resolution Note:

    This particular case has been investigated thoroughly and we have decided, in the interests of protecting the stability and features of Unity for users that rely upon the affected versions, to not address this fix for the time being. We understand that this will cause problems for some users, and so may address in a future version.

Comments (5)

  1. yoyobbi

    Mar 01, 2019 22:09

    The full error is as follows. Something is messed up with built-in package management. I haven't yet figured out a workaround:

    error CS1704: An assembly with the same name `UnityEngine.UI' has already been imported. Consider removing one of the references or sign the assembly
    C:/Program Files/Unity/Hub/Editor/2018.2.15f1/Editor/Data/UnityExtensions/Unity/GUISystem/UnityEngine.UI.dll (Location of the symbol related to previous error)
    C:/Program Files/Unity/Hub/Editor/2018.2.15f1/Editor/Data/UnityExtensions/Unity/GUISystem/Standalone/UnityEngine.UI.dll (Location of the symbol related to previous error)
    error CS1704: An assembly with the same name `UnityEngine.Timeline' has already been imported. Consider removing one of the references or sign the assembly
    C:/Program Files/Unity/Hub/Editor/2018.2.15f1/Editor/Data/UnityExtensions/Unity/Timeline/RuntimeEditor/UnityEngine.Timeline.dll (Location of the symbol related to previous error)
    C:/Program Files/Unity/Hub/Editor/2018.2.15f1/Editor/Data/UnityExtensions/Unity/Timeline/Runtime/UnityEngine.Timeline.dll (Location of the symbol related to previous error)
    error CS1704: An assembly with the same name `UnityEngine.Networking' has already been imported. Consider removing one of the references or sign the assembly
    C:/Program Files/Unity/Hub/Editor/2018.2.15f1/Editor/Data/UnityExtensions/Unity/Networking/UnityEngine.Networking.dll (Location of the symbol related to previous error)
    C:/Program Files/Unity/Hub/Editor/2018.2.15f1/Editor/Data/UnityExtensions/Unity/Networking/Standalone/UnityEngine.Networking.dll (Location of the symbol related to previous error)
    error CS1704: An assembly with the same name `UnityEngine.GoogleAudioSpatializer' has already been imported. Consider removing one of the references or sign the assembly
    C:/Program Files/Unity/Hub/Editor/2018.2.15f1/Editor/Data/UnityExtensions/Unity/UnityGoogleAudioSpatializer/Runtime/UnityEngine.GoogleAudioSpatializer.dll (Location of the symbol related to previous error)
    C:/Program Files/Unity/Hub/Editor/2018.2.15f1/Editor/Data/UnityExtensions/Unity/UnityGoogleAudioSpatializer/RuntimeEditor/UnityEngine.GoogleAudioSpatializer.dll (Location of the symbol related to previous error)
    error CS1704: An assembly with the same name `UnityEngine.HoloLens' has already been imported. Consider removing one of the references or sign the assembly
    C:/Program Files/Unity/Hub/Editor/2018.2.15f1/Editor/Data/UnityExtensions/Unity/UnityHoloLens/Runtime/UnityEngine.HoloLens.dll (Location of the symbol related to previous error)
    C:/Program Files/Unity/Hub/Editor/2018.2.15f1/Editor/Data/UnityExtensions/Unity/UnityHoloLens/RuntimeEditor/UnityEngine.HoloLens.dll (Location of the symbol related to previous error)

    Compilation failed: 5 error(s), 0 warnings

  2. yoyobbi

    Mar 01, 2019 22:06

    Getting this error opening an existing project in 2018.2.15f1, after having installed a second copy of 2018.2.15f1 with il2cpp support enabled. Can't open the existing (Mono-based) project in either instance.

  3. cgrow67

    Aug 01, 2018 23:12

    Getting this same problem updating from 2018.1.8f1 to 2019.1.9f1

  4. mikael_kalms

    Feb 06, 2018 12:05

    Getting something very similar in 2017.3.0f3 - a collision with UnityEngine.Networking DLL. The project has been upgraded 5.5.0f3 -> 5.6.1f1 -> 2017.1.0f3 -> 2017.3.0f3.

    We noticed this problem several weeks after upgrading, when we attempted to build the game on a machine which had both native Windows and the Windows Store build support installed.

    Unity QA has confirmed that there is a regression.

  5. sosh

    Oct 31, 2017 09:49

    Getting this in 2017.2.0f3, upgrading project from 5.6

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