Error when trying to build for Android in Unity 2021, not present in Unity 2019

[boasbakker123]

This is the error:
Building \Library\Bee\artifacts\unitylinker_xy1a.traceevents failed with output:
C:\Program Files\Unity\Hub\Editor\2021.3.10f1\Editor\Data\il2cpp\build\deploy\UnityLinker.exe --search-directory=Temp/StagingArea/Data/Managed --out=Library/Bee/artifacts/Android/ManagedStripped --include-link-xml=Temp/StagingArea/Data/Managed\TypesInScenes.xml --include-link-xml=Temp/StagingArea/Data/Managed\SerializedTypes.xml --include-link-xml=\Assets\PlayFabSDK\link.xml --include-link-xml=C:/Program Files/Unity/Hub/Editor/2021.3.10f1/Editor/Data/PlaybackEngines/AndroidPlayer/Tools/AndroidNativeLink.xml --include-directory=Temp/StagingArea/Data/Managed --profiler-report --profiler-output-file=Library/Bee/artifacts/unitylinker_xy1a.traceevents --dotnetprofile=unityaot-linux --dotnetruntime=Il2Cpp --platform=Android --use-editor-options --enable-engine-module-stripping --engine-stripping-flag=EnableUnityConnect --engine-stripping-flag=EnableCrashReporting --engine-modules-asset-file=C:/Program Files/Unity/Hub/Editor/2021.3.10f1/Editor/Data/PlaybackEngines/AndroidPlayer/modules.asset --editor-data-file=Temp/StagingArea/Data/Managed/EditorToUnityLinkerData.json --include-unity-root-assembly=Temp/StagingArea/Data/Managed/Assembly-CSharp-firstpass.dll --include-unity-root-assembly=Temp/StagingArea/Data/Managed/Assembly-CSharp.dll --include-unity-root-assembly=Temp/StagingArea/Data/Managed/UnityEngine.UI.dll --include-unity-root-assembly=Temp/StagingArea/Data/Managed/NativeGallery.Runtime.dll --include-unity-root-assembly=Temp/StagingArea/Data/Managed/PlayFab.dll --include-unity-root-assembly=Temp/StagingArea/Data/Managed/Unity.TextMeshPro.dll --print-command-line --enable-analytics
Stack overflow.
at Mono.Cecil.Metadata.RowEqualityComparer.GetHashCode(Mono.Cecil.Metadata.Row2<System.String,System.String>) at System.Collections.Generic.Dictionary2[[Mono.Cecil.Metadata.Row2[[System.__Canon, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.__Canon, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], Mono.Cecil, Version=0.10.0.0, Culture=neutral, PublicKeyToken=50cebf1cceb9d05e],[System.__Canon, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].FindValue(Mono.Cecil.Metadata.Row2<System.__Canon,System.__Canon>)
at System.Collections.Generic.Dictionary2[[Mono.Cecil.Metadata.Row2[[System.__Canon, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.__Canon, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], Mono.Cecil, Version=0.10.0.0, Culture=neutral, PublicKeyToken=50cebf1cceb9d05e],[System.__Canon, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].TryGetValue(Mono.Cecil.Metadata.Row`2<System.__Canon,System.__Canon>, System.__Canon ByRef)
at Mono.Cecil.TypeDefinitionCollection.GetType(System.String, System.String)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.ExportedTypeResolver.Resolve(Mono.Cecil.ModuleDefinition, Mono.Cecil.TypeReference)
at Unity.Cecil.Awesome.BaseWindowsRuntimeAwareMetadataResolver.Resolve(Mono.Cecil.TypeRefere

BuildFailedException: Incremental Player build failed!
UnityEditor.Modules.BeeBuildPostprocessor.PostProcess (UnityEditor.Modules.BuildPostProcessArgs args) (at <99feab6f3db6407493924fe4a179a95b>:0)
UnityEditor.Modules.DefaultBuildPostprocessor.PostProcess (UnityEditor.Modules.BuildPostProcessArgs args, UnityEditor.BuildProperties& outProperties) (at <99feab6f3db6407493924fe4a179a95b>:0)
UnityEditor.Android.AndroidBuildPostprocessor.PostProcess (UnityEditor.Modules.BuildPostProcessArgs args, UnityEditor.BuildProperties& outProperties) (at <254d6ba8d2224b2793130e21dc037be2>:0)
UnityEditor.PostprocessBuildPlayer.Postprocess (UnityEditor.BuildTargetGroup targetGroup, UnityEditor.BuildTarget target, System.Int32 subtarget, System.String installPath, System.String companyName, System.String productName, System.Int32 width, System.Int32 height, UnityEditor.BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry, UnityEditor.Build.Reporting.BuildReport report) (at <99feab6f3db6407493924fe4a179a95b>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)

Build completed with a result of ‘Failed’ in 150 seconds (149519 ms)
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)

UnityEditor.BuildPlayerWindow+BuildMethodException: 3 errors
at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (UnityEditor.BuildPlayerOptions options) [0x002da] in <99feab6f3db6407493924fe4a179a95b>:0
at UnityEditor.BuildPlayerWindow.CallBuildMethods (System.Boolean askForBuildLocation, UnityEditor.BuildOptions defaultBuildOptions) [0x00080] in <99feab6f3db6407493924fe4a179a95b>:0
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)

[Kurt-Dekker]

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 .

If it’s not that, then here’s how to troubleshoot:

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

If it does NOT build, then go fix your Unity installation, or your other tools, such as Android SDK, NDK, JDK, etc.

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 that subsystem.