Solved my issue. Most likely it was because the "Jason's Software" location. Likely a problem with the apostrophe. Reinstalled right on my C drive and no issues. No wonder no one else had the same problem!

I get a Win32Exception regarding mono.exe and Commandline = mcs.exe the instant I import any assets for a tutorial from unity. Not sure if it's related.

Happens in multiple versions of Unity and always when assets are imported. Win7 64, Current ver of Unity and others post ver 5. "Survival Shooter tutorial" in Asset Store, imported via same.

Win32Exception: ApplicationName='"C:\Jason's Software\Unity\Editor\Data\MonoBleedingEdge\bin\mono.exe"', CommandLine='"C:\Jason's Software\Unity\Editor\Data\MonoBleedingEdge\lib\mono\4.5\mcs.exe" @Temp/UnityTempFile-a69ad0c9ed89862499a18827f3ac3d26', CurrentDirectory='C:/Jason's Software/Unity/Unity_Projects/Tut_2A/Assets/..'
System.Diagnostics.Process.Start_noshell (System.Diagnostics.ProcessStartInfo startInfo, System.Diagnostics.Process process)
System.Diagnostics.Process.Start_common (System.Diagnostics.ProcessStartInfo startInfo, System.Diagnostics.Process process)
System.Diagnostics.Process.Start ()
(wrapper remoting-invoke-with-check) System.Diagnostics.Process:Start ()
UnityEditor.Utils.Program.Start (System.EventHandler exitCallback) (at C:/buildslave/unity/build/Editor/Mono/Utils/Program.cs:44)
UnityEditor.Utils.Program.Start () (at C:/buildslave/unity/build/Editor/Mono/Utils/Program.cs:28)
UnityEditor.Scripting.Compilers.MonoScriptCompilerBase.StartCompiler (BuildTarget target, System.String compiler, System.Collections.Generic.List`1 arguments, Boolean setMonoEnvironmentVariables, System.String monodistro) (at C:/buildslave/unity/build/Editor/Mono/Scripting/Compilers/MonoScriptCompilerBase.cs:33)
UnityEditor.Scripting.Compilers.MonoCSharpCompiler.StartCompiler () (at C:/buildslave/unity/build/Editor/Mono/Scripting/Compilers/MonoCSharpCompiler.cs:59)
UnityEditor.Scripting.Compilers.ScriptCompilerBase.BeginCompiling () (at C:/buildslave/unity/build/Editor/Mono/Scripting/Compilers/ScriptCompilerBase.cs:40)
UnityEditor.Scripting.ScriptCompilation.CompilationTask.QueuePendingAssemblies () (at C:/buildslave/unity/build/Editor/Mono/Scripting/ScriptCompilation/CompilationTask.cs:192)
UnityEditor.Scripting.ScriptCompilation.CompilationTask.Poll () (at C:/buildslave/unity/build/Editor/Mono/Scripting/ScriptCompilation/CompilationTask.cs:138)
UnityEditor.Scripting.ScriptCompilation.EditorCompilation.CompileScripts (UnityEditor.Scripting.ScriptCompilation.ScriptAssemblySettings scriptAssemblySettings, System.String tempBuildDirectory, BuildFlags buildflags, .TargetAssembly[]& notCompiledTargetAssemblies) (at C:/buildslave/unity/build/Editor/Mono/Scripting/ScriptCompilation/EditorCompilation.cs:419)
UnityEditor.Scripting.ScriptCompilation.EditorCompilation.CompileScripts (EditorScriptCompilationOptions definesOptions, BuildTargetGroup platformGroup, BuildTarget platform) (at C:/buildslave/unity/build/Editor/Mono/Scripting/ScriptCompilation/EditorCompilation.cs:317)
UnityEditor.Scripting.ScriptCompilation.EditorCompilationInterface.CompileScripts (EditorScriptCompilationOptions definesOptions, BuildTargetGroup platformGroup, BuildTarget platform) (at C:/buildslave/unity/build/Editor/Mono/Scripting/ScriptCompilation/EditorCompilationInterface.cs:80)

Issue is present in Unity 5.6.1 on OS X as well - we just grabbed the AssetBundle Manager for our project and hit this issue immediately upon trying to run the tutorial samples. Issue indeed seems to be that the path to Mono ("/Applications/Unity5.6.1/Unity.app/Contents/Frameworks/MonoBleedingEdge/bin/mono" in this case) is not valid. It should be "/Applications/Unity5.6.1/Unity.app/Contents/MonoBleedingEdge/bin/mono" as mentioned above.

In my case I worked around this by doing the following:
$ cd '/Applications/Unity5.6.1/Unity.app/Contents/Frameworks'
$ ln -s ../MonoBleedingEdge ./MonoBleedingEdge

(just in case anyone else happens upon this thread as I did)

To start AssetBundleServer.exe without crashing with a HttpListener exception, the following command needs to be run in a command window: netsh http add urlacl url=http://*:7888/ user=Everyone listen=yes

However, Unity still cannot see the server, but that's another issue.

Unity 5.6.0f3 - Windows 10

Asset Bundle Server fails to start. The event log in windows states:

Application: AssetBundleServer.exe Framework Version: v4.0.30319 Description: The process was terminated due to an unhandled exception. Exception Info: System.Net.HttpListenerException at System.Net.HttpListener.AddAllPrefixes() at System.Net.HttpListener.Start() at AssetBundleServer.MainClass.Main(System.String[])

We are using AssetBundle variants so this is a blocker now.

FYI:
I have the same problem and has solved it. It's like what DEVTONY said but have a little bit different, instead of
return Path.Combine(editorAppPath, "Contents");
you should change to
return Path.Combine("Contents", "");

Test env is Unity 5.4.1 pro version

Issue still present in 5.4.0b16

Problem is MonoBleedingEdge is no longer located in the Frameworks folder as referenced by AssetBundleManager/Editor/ExecuteInternalMono.cs line 20 in the AssetBundle Manager & Example Scenes package (https://www.assetstore.unity3d.com/en/#!/content/45836).

A local workaround (maybe using something like #if UNITY_5_4_OR_NEWER for editor backwards compatibility) is to replace this:
return Path.Combine(editorAppPath, Path.Combine("Contents", "Frameworks"));
with this:
return Path.Combine(editorAppPath, "Contents");
in the aforementioned file.

If it works, when you run Assets/AssetBundles/Local AssetBundle Server, you'll see a new 'mono' process appear in Activity Monitor w/ the Open Files page containing something like this:
/Applications/Unity/Unity.app/Contents/MonoBleedingEdge/bin/mono
and
<your project's location>/Assets/AssetBundleManager/Editor/AssetBundleServer.exe