Unity Multiplayer Error: Copying assembly from 'Temp/com.unity.multiplayer-hlapi.Runtime.dll' to 'Library/ScriptAssemb

Hello everyone, I tested everything today to fix that error:

Copying assembly from 'Temp/com.unity.multiplayer-hlapi.Runtime.dll' to 'Library/ScriptAssemblies/com.unity.multiplayer-hlapi.Runtime.dll' failed

Mirror asset got me the same error Temp/mirror.dll.

Ive disabled my antivirus, reinstall unity, that error appear when compiling and follow unable to start by play in-editor function.

Please help me, im going to lost hundred of work staff.

Thanks

 

Solution:

1. Download "Mirror" from asset.
2. Replace all classic Networking component of all gameobjects/prefab by Mirror scripts component (networkmanager, networkidentity, networktransform, ....).
3. In visual studio code at right on Solution references, search "hlapi" and remove all hlapi references.
4. Replace all your "using UnityEditor.Networking" and "using UnityEditor.Networking.X" by "using Mirror;"
5.

 

I had the same problem, and tried that solution. No luck... I still get

Copying assembly from 'Temp/Mirror.dll' to 'Library/ScriptAssemblies/Mirror.dll' failed

 

... and it turned out to be Dropbox. I paused syncing, and the problem went away.

Leaving this note in case others encounter the same problem.

 

Copying assembly from 'Temp/Unity.Timeline.dll' to 'Library/ScriptAssemblies/Unity.Timeline.dll' failed

Copying assembly from 'Temp/Unity.TextMeshPro.dll' to 'Library/ScriptAssemblies/Unity.TextMeshPro.dll' failed

and missing package manager
unity V2019.1.0f2

I'm new to unity and before even started to use I encounter these errors, so ...

 

Same problem here.

Copying assembly from 'Temp/com.unity.multiplayer-hlapi.Runtime.dll' to 'Library/ScriptAssemblies/com.unity.multiplayer-hlapi.Runtime.dll' failed

This is while downloading and installing "Post Processing" version 2.1.6 using Package manager in Unity 2019.1.0f2, this error prevents from using "PostProcessLayer"

 

I got the same issue, after i done the TextMeshPro error. I just did the following :
In Unity go to Window -> Package Manager, Find MultiPlayer HLAPI, then delete it, and reinstall.
When i first tried i installed older version (1.0.0), then i uninstalled, and reinstalled the normal version.
After i run the unity project normally and it worked.
Hopefully helped.

 

This worked for me. Thanks.

 

I got the same issue, I just did the following :
In Unity go to Window -> Package Manager, Find MultiPlayer HLAPI, then delete it, and reinstall.
After i run the unity project normally and it worked.
Hopefully helped.

 

I got a complete project in a local git repo and got the same issue (MultiPlayer HLAPI).
Removing / installing ot from package manager did it for me.

 

Works for me as well. Thanks

 

Unhappily in getting this error trying to reinstall SteamVR 2.3.2. after uninstall. Unity wont install 'Steam VR input' under windows. Out of ideas, suggestions?

 

, remove the file
Library/ScriptAssemblies/com.unity.multiplayer-hlapi.Runtime.dll
and now build works again, once only. The file-removal procedure has to be repeated for every build

 

I had the same error occur to me. All i had to do was update the MultiPlayer HLAPI version to the latest and re-import the package I was trying to import. Go to Window --> Package Manager and find MultiPlayer HLAPI. Check the versions and update it to latest (worked in my case)

 

This some problem with my unity 2019.2.0f1, I fixed updating Multiplayer HLAPI 1.0.2 to 1.0.4 from Windows > Manage Packages.

 

I have the same error
Copying assembly from 'Temp/com.unity.multiplayer-hlapi.Runtime.dll' to 'Library/ScriptAssemblies/com.unity.multiplayer-hlapi.Runtime.dll' failed

 

What worked for me was to set Project Settings -> Player -> Api Compatibility Level to .NET 4.x