Reproduction steps:
1. Download project from comment and open in Unity
2. Download 28.0.0-rc1 or 28.0.0-rc2 build tools and install
3. Go to Files -> Build Settings
4. Build And Run

Expected: for the project to be built successfully
Actual: build fails because of an error

Reproduced on: 2018.2.0a1; 2018.2.0b1; 2018.2.0b7; 2018.3.0a1
Not reproducible on: 2017.1.4p1; 2017.2.3p1; 2017.4.5f1; 2018.1.4f1
Regression introduced: 2018.2.0a1

Note:
Issue disappears after uninstalling 28.0.0-rc1 or 28.0.0-rc2.
Player Settings property Target API Level has to be set to Automatic (highest installed) for the issue to be reproducible.
Error:
FormatException: Input string was not in the correct format
System.Int32.Parse (System.String s) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System/Int32.cs:629)
System.Version..ctor (System.String version) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System/Version.cs:109)
UnityEditor.Android.Utils.ParseVersion (System.String version)
UnityEditor.Android.AndroidComponentProperties.get_PackageRevision ()
UnityEditor.Android.AndroidComponentProperties.GetPackageRevision (System.String directory)
UnityEditor.Android.AndroidSDKTools.BuildToolsVersion ()
UnityEditor.Android.PostProcessor.Tasks.CheckAndroidSDK+SDKBuildToolsDetector.GetVersion (UnityEditor.Android.AndroidSDKTools sdkTools, UnityEditor.Android.AndroidJavaTools javaTools)
UnityEditor.Android.PostProcessor.Tasks.CheckAndroidSDK+SDKComponentDetector.Detect (UnityEditor.Android.AndroidSDKTools sdkTools, UnityEditor.Android.AndroidJavaTools javaTools, System.Version minVersion, UnityEditor.Android.PostProcessor.ProgressHandler onProgress)
UnityEditor.Android.PostProcessor.Tasks.CheckAndroidSDK.EnsureSDKComponentVersion (UnityEditor.Android.AndroidJavaTools javaTools, System.Version minVersion, UnityEditor.Android.PostProcessor.Tasks.SDKComponentDetector detector)
UnityEditor.Android.PostProcessor.Tasks.CheckAndroidSDK.EnsureSDKComponentVersion (UnityEditor.Android.AndroidJavaTools javaTools, Int32 minVersion, UnityEditor.Android.PostProcessor.Tasks.SDKComponentDetector detector)
UnityEditor.Android.PostProcessor.Tasks.CheckAndroidSDK.Execute (UnityEditor.Android.PostProcessor.PostProcessorContext context)
UnityEditor.Android.PostProcessor.PostProcessRunner.RunAllTasks (UnityEditor.Android.PostProcessor.PostProcessorContext context)
UnityEditor.Android.PostProcessAndroidPlayer.PrepareForBuild (BuildOptions options, BuildTarget target)
UnityEditor.Android.AndroidBuildPostprocessor.PrepareForBuild (BuildOptions options, BuildTarget target)
UnityEditor.PostprocessBuildPlayer.PrepareForBuild (BuildOptions options, BuildTargetGroup targetGroup, BuildTarget target) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/PostprocessBuildPlayer.cs:106)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

Fixed on: 2018.3.0a10