ArgumentException: The specified path is not of a legal form (empty)

[gregg_unity270]

I get an error (seen below) whenever I attempt to do a build of the project.

Has anyone encountered this problem before? If so, how did you get around it?

Unity Version: 2020.3.48f1
Burst Version: 1.8.4
ArgumentException: The specified path is not of a legal form (empty).

System.IO.Path.InsecureGetFullPath (System.String path) (at <695d1cc93cca45069c528c15c9fdd749>:0) System.IO.Path.GetFullPath (System.String path) (at <695d1cc93cca45069c528c15c9fdd749>:0) Unity.Burst.Editor.BurstLoader.TryResolvePath (System.String path, System.Collections.Generic.Dictionary`2[TKey,TValue] packagesLookup, System.String& resolvedPath) (at Library/PackageCache/com.unity.burst@1.8.4/Runtime/Editor/BurstLoader.cs:554) Unity.Burst.Editor.BurstLoader.GetAssemblyFolders () (at Library/PackageCache/com.unity.burst@1.8.4/Runtime/Editor/BurstLoader.cs:493) Unity.Burst.Editor.BurstLoader…cctor () (at Library/PackageCache/com.unity.burst@1.8.4/Runtime/Editor/BurstLoader.cs:136) Rethrow as TypeInitializationException: The type initializer for ‘Unity.Burst.Editor.BurstLoader’ threw an exception. Unity.Burst.Editor.BurstAotCompiler.OnPostBuildPlayerScriptDLLsImpl (Unity.Burst.Editor.BurstAotCompiler+BurstAOTSettings settings, UnityEditor.Compilation.Assembly[ ] playerAssemblies) (at Library/PackageCache/com.unity.burst@1.8.4/Editor/BurstAotCompiler.cs:449) Unity.Burst.Editor.BurstAOTCompilerPostprocessor.DoGenerate (UnityEditor.Compilation.Assembly[ ] assemblies) (at Library/PackageCache/com.unity.burst@1.8.4/Editor/BurstAotCompiler.cs:265) Unity.Burst.Editor.BurstAOTCompilerPostprocessor.OnPostBuildPlayerScriptDLLs (UnityEditor.Build.Reporting.BuildReport report) (at Library/PackageCache/com.unity.burst@1.8.4/Editor/BurstAotCompiler.cs:189) UnityEditor.Build.BuildPipelineInterfaces.OnPostBuildPlayerScriptDLLs (UnityEditor.Build.Reporting.BuildReport report) (at <25578071f6e44201aac745680e5c8dfc>:0) UnityEditor.BuildPipeline:BuildPlayer(EditorBuildSettingsScene[ ], String, BuildTarget, BuildOptions)

[Kurt-Dekker]

Are you using burst? If so, make sure all the parts of it are up to date and compatible with your version of Unity.

If you’re not using burst, remove it.

Extra unwanted packages in new projects (collab, testing, rider and other junk):

Temp/UnityEngine.TestRunner.dll Error

Recent versions of unity have an annoying habit of crapping useless packages into your project. When those packages inevitably have errors, this sort of thing happens. I have railed about it before. Go into the package manager and remove crap you don’t need, like the entire test runner and collab and whatnot. If you feel brave you can hand-edit the Packages/manifest.json file a lot faster than using the laggy package manager interface that only lets you remove one package at a time: [7287748-…

About the fastest way I have found to make a project and avoid all this noise is to create the project, then as soon as you see the files appear, FORCE-STOP (hard-kill) Unity (with the Activity Manager or Task Manager), then go hand-edit the Packages/manifest.json file as outlined in the above post, then reopen Unity.

Sometimes the package system gets borked from all this unnecessary churn and requires the package cache to be cleared:

Unity3D Package Cache errors(?)

[gregg_unity270]

Hi Kurt, thanks for the reply!

Burst is needed in the project, I’ve also cleared the package cache and still produces the same error. What’s also strange is re-adding Burst, after removing it, in my package manager gives me the same error above (which is ArgumentException: The specified path is not of a legal form (empty). ).

I’m currently deleting and reinstalling/reimporting everything again and hoping it fixes the problem.

[Kurt-Dekker]

Sounds like maybe you’re using wiggy-whacky characters in your path.

If that’s the case, don’t do that. Use only A to Z and 0 to 9 in directory / file / path names.

How to troubleshoot build failures:

First, make a blank project with a single blank scene and prove that it builds successfully.

If the blank project does NOT build, go fix your Unity installation or your other tools, such as Android SDK, NDK, JDK, etc. It may even be necessary to change to a different version of Unity3D. It is generally best to stay with LTS versions of Unity3D.

Until you can build a blank project to the target platform, don’t fiddle with anything else.

Once you can build a blank project, now bisect the problem by bringing over parts of your current project and building it one subsystem at a time, perhaps stubbing things out that might trigger compiler errors.

Most often things that prevent building are third-party libraries such as Firebase.

Once you identify the subsystem, go to the documentation for it and make sure you are doing it correctly.

It may also be helpful to work through a tutorial or two for whatever subsystem is making the build fail.

Android build not building:

Recently (circa July 2022) there have been reports of Unity’s installer failing to install the Android Tools.

Can't build for Android

Latest Hub 3.2.0 in combination with Unity 2021.3.6 can't build for Android because there is a missing Tools folder inside *Editor\Data\PlaybackEngines\AndroidPlayer* so Unity can't find gradle. That folder is simply not created during the installation. The workaround is to copy the whole Tools folder from the previous Unity version or if you don't have the previous version then do what [mention|1j+oWeNEPCI6ejbN15sncw==] says in the post below .

Here was how I brought up Unity2020.3.41 and the Android SDK 31 on October 30, 2022:

.AAB Build Targeting API Level 33 on Unity 2021.3.8 with JDK 1.8.

Hey, coincidentally I just upgraded to Android SDK31 today… why not wait until nearly the last minute? It was a wild ride, took most of the day. Let me tell you what I did, what I found. First of all, I’m using Unity2020.3.41 (hereinafter referred to Unity*) because that’s all the further I need to go forward right now. I found that Unity* only accepts up to SDK30.0.3 tools, but will build using those tools and SDK31. Next I found that Android Studio will not install anything except Android …

Android Gradle errors and other related stuff:

Unity Gradle bug... please help

Fix:

[gregg_unity270]

I can build a blank project fine, though as you said, I did add Burst 1.8.4 and displayed the same error without even building it.

What seem to worked on the blank project and the current project (and their standalone builds) are Burst 1.6.6 and Burst 1.8.0. Burst 1.8.1 up to 1.8.4 does not work as they give compiler errors.

So, I think I’ll go with Burst 1.8.0 instead.

Thanks for the help Kurt!