Crash in macOS: TypeLoadException: Could not resolve type Cake.Core.CakeTaskBuilder`1, Cake.Core, Version=0.26.1.0, Culture=neutral, PublicKeyToken=null

### What You Are Seeing?
A crash.

I try to build the repository ZXing.Net.Mobile, which has a stock build.sh file for bootstrapping CAKE. The log:
```
$ ./build.sh
Restoring tools from NuGet...
Feeds used:
/Users/andres/.nuget/packages/
https://www.myget.org/F/nethereum/api/v3/index.json
https://api.nuget.org/v3/index.json

All packages listed in /Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/packages.config are already installed.
Running Cake...
The assembly 'Cake.Android.SdkManager, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null'
is referencing an older version of Cake.Core (0.26.1).
For best compatibility it should target Cake.Core version 0.28.0.
The assembly 'Cake.XCode, Version=4.0.0.0, Culture=neutral, PublicKeyToken=null'
is referencing an older version of Cake.Core (0.26.1).
For best compatibility it should target Cake.Core version 0.28.0.
The assembly 'Cake.Xamarin, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null'
is referencing an older version of Cake.Core (0.26.1).
For best compatibility it should target Cake.Core version 0.28.0.
The assembly 'Cake.Xamarin.Build, Version=4.0.1.0, Culture=neutral, PublicKeyToken=null'
is referencing an older version of Cake.Core (0.26.1).
For best compatibility it should target Cake.Core version 0.28.0.
The assembly 'Cake.SemVer, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null'
is referencing an older version of Cake.Core (0.26.1).
For best compatibility it should target Cake.Core version 0.28.0.
Error: Could not resolve type with token 01000016 (from typeref, class/assembly Cake.Core.CakeTaskBuilder`1, Cake.Core, Version=0.26.1.0, Culture=neutral, PublicKeyToken=null)
```

### What is Expected?
To not crash?

### What version of Cake are you using?
The last one? build.sh seems to download the last one. Which at the time of writing seems to be 0.30.0.

### Are you running on a 32 or 64 bit system?
64 I guess.

### What environment are you running on? Windows? Linux? Mac?
macOS

### Are you running on a CI Server? If so, which one?
No

### How Did You Get This To Happen? (Steps to Reproduce)
Clone https://github.com/Redth/ZXing.Net.Mobile , run its build.sh.

### Output Log
Log with `--verbosity=diagnostic`:

```
$ ./build.sh
Restoring tools from NuGet...
Feeds used:
/Users/andres/.nuget/packages/
https://www.myget.org/F/nethereum/api/v3/index.json
https://api.nuget.org/v3/index.json

All packages listed in /Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/packages.config are already installed.
Running Cake...
Module directory does not exist.
NuGet.config not found.
Analyzing build script...
Analyzing /Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/build.cake...
Processing build script...
Installing tools...
GET https://www.myget.org/F/nethereum/api/v3/registration1/xamarincomponent/index.json
NotFound https://www.myget.org/F/nethereum/api/v3/registration1/xamarincomponent/index.json 1404ms
CACHE https://api.nuget.org/v3/registration3-gz-semver2/xamarincomponent/index.json
Found package 'XamarinComponent 1.1.0.65' in '/Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools'.
Package XamarinComponent.1.1.0.65 has already been installed.
Successfully installed 'XamarinComponent 1.1.0.65' to /Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools
Executing nuget actions took 18.95 ms
Installing addins...
GET https://www.myget.org/F/nethereum/api/v3/registration1/cake.android.sdkmanager/index.json
NotFound https://www.myget.org/F/nethereum/api/v3/registration1/cake.android.sdkmanager/index.json 1106ms
CACHE https://api.nuget.org/v3/registration3-gz-semver2/cake.android.sdkmanager/index.json
Found package 'Cake.Android.SdkManager 3.0.0' in '/Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins'.
Package Cake.Android.SdkManager.3.0.0 has already been installed.
Successfully installed 'Cake.Android.SdkManager 3.0.0' to /Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins
Executing nuget actions took 0.84 ms
The addin Cake.Android.SdkManager will reference Cake.Android.SdkManager.dll.
GET https://www.myget.org/F/nethereum/api/v3/registration1/cake.xcode/index.json
NotFound https://www.myget.org/F/nethereum/api/v3/registration1/cake.xcode/index.json 1063ms
CACHE https://api.nuget.org/v3/registration3-gz-semver2/cake.xcode/index.json
Found package 'Cake.XCode 4.0.0' in '/Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins'.
Package Cake.XCode.4.0.0 has already been installed.
Successfully installed 'Cake.XCode 4.0.0' to /Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins
Executing nuget actions took 0.8 ms
The addin Cake.XCode will reference Cake.XCode.dll.
GET https://www.myget.org/F/nethereum/api/v3/registration1/cake.xamarin/index.json
NotFound https://www.myget.org/F/nethereum/api/v3/registration1/cake.xamarin/index.json 1234ms
CACHE https://api.nuget.org/v3/registration3-gz-semver2/cake.xamarin/index.json
Found package 'Cake.Xamarin 3.0.0' in '/Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins'.
Package Cake.Xamarin.3.0.0 has already been installed.
Successfully installed 'Cake.Xamarin 3.0.0' to /Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins
Executing nuget actions took 0.84 ms
The addin Cake.Xamarin will reference Cake.Xamarin.dll.
GET https://www.myget.org/F/nethereum/api/v3/registration1/cake.xamarin.build/index.json
NotFound https://www.myget.org/F/nethereum/api/v3/registration1/cake.xamarin.build/index.json 1108ms
CACHE https://api.nuget.org/v3/registration3-gz-semver2/cake.xamarin.build/index.json
Found package 'Cake.Xamarin.Build 4.0.1' in '/Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins'.
Package Cake.Xamarin.Build.4.0.1 has already been installed.
Successfully installed 'Cake.Xamarin.Build 4.0.1' to /Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins
Executing nuget actions took 0.82 ms
The addin Cake.Xamarin.Build will reference Cake.Xamarin.Build.dll.
GET https://www.myget.org/F/nethereum/api/v3/registration1/cake.semver/index.json
NotFound https://www.myget.org/F/nethereum/api/v3/registration1/cake.semver/index.json 1190ms
CACHE https://api.nuget.org/v3/registration3-gz-semver2/cake.semver/index.json
Found package 'Cake.SemVer 3.0.0' in '/Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins'.
Package Cake.SemVer.3.0.0 has already been installed.
Successfully installed 'Cake.SemVer 3.0.0' to /Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins
Executing nuget actions took 0.82 ms
The addin Cake.SemVer will reference Cake.SemVer.dll.
GET https://www.myget.org/F/nethereum/api/v3/registration1/cake.filehelpers/index.json
NotFound https://www.myget.org/F/nethereum/api/v3/registration1/cake.filehelpers/index.json 1022ms
CACHE https://api.nuget.org/v3/registration3-gz-semver2/cake.filehelpers/index.json
Found package 'Cake.FileHelpers 3.1.0' in '/Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins'.
Package Cake.FileHelpers.3.1.0 has already been installed.
Successfully installed 'Cake.FileHelpers 3.1.0' to /Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins
Executing nuget actions took 0.89 ms
The addin Cake.FileHelpers will reference Cake.FileHelpers.dll.
GET https://www.myget.org/F/nethereum/api/v3/registration1/cake.monoapitools/index.json
NotFound https://www.myget.org/F/nethereum/api/v3/registration1/cake.monoapitools/index.json 1074ms
CACHE https://api.nuget.org/v3/registration3-gz-semver2/cake.monoapitools/index.json
Found package 'Cake.MonoApiTools 3.0.1' in '/Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins'.
Package Cake.MonoApiTools.3.0.1 has already been installed.
Successfully installed 'Cake.MonoApiTools 3.0.1' to /Users/andres/Documents/Code/gwalletFRONTEND/build/ZXing.Net.Mobile/tools/Addins
Executing nuget actions took 0.92 ms
The addin Cake.MonoApiTools will reference Cake.MonoApiTools.dll.
Verifying assembly 'Cake.Android.SdkManager, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null'.
The assembly 'Cake.Android.SdkManager, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null'
is referencing an older version of Cake.Core (0.26.1).
For best compatibility it should target Cake.Core version 0.28.0.
Verifying assembly 'Cake.XCode, Version=4.0.0.0, Culture=neutral, PublicKeyToken=null'.
The assembly 'Cake.XCode, Version=4.0.0.0, Culture=neutral, PublicKeyToken=null'
is referencing an older version of Cake.Core (0.26.1).
For best compatibility it should target Cake.Core version 0.28.0.
Verifying assembly 'Cake.Xamarin, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null'.
The assembly 'Cake.Xamarin, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null'
is referencing an older version of Cake.Core (0.26.1).
For best compatibility it should target Cake.Core version 0.28.0.
Verifying assembly 'Cake.Xamarin.Build, Version=4.0.1.0, Culture=neutral, PublicKeyToken=null'.
The assembly 'Cake.Xamarin.Build, Version=4.0.1.0, Culture=neutral, PublicKeyToken=null'
is referencing an older version of Cake.Core (0.26.1).
For best compatibility it should target Cake.Core version 0.28.0.
Verifying assembly 'Cake.SemVer, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null'.
The assembly 'Cake.SemVer, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null'
is referencing an older version of Cake.Core (0.26.1).
For best compatibility it should target Cake.Core version 0.28.0.
Verifying assembly 'Cake.FileHelpers, Version=3.1.0.0, Culture=neutral, PublicKeyToken=null'.
Verifying assembly 'Cake.MonoApiTools, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null'.
Error: System.TypeLoadException: Could not resolve type with token 01000016 (from typeref, class/assembly Cake.Core.CakeTaskBuilder`1, Cake.Core, Version=0.26.1.0, Culture=neutral, PublicKeyToken=null)
at (wrapper managed-to-native) System.Reflection.MonoMethodInfo.get_parameter_info(intptr,System.Reflection.MemberInfo)
at System.Reflection.MonoMethodInfo.GetParametersInfo (System.IntPtr handle, System.Reflection.MemberInfo member) [0x00000] in :0
at System.Reflection.MonoMethod.GetParameters () [0x00000] in :0
at Cake.Core.Scripting.ScriptAliasFinder+d__4.MoveNext () [0x00070] in <1a12afcf649f4de8ab5d15d82d4f6310>:0
at Cake.Core.Scripting.ScriptAliasFinder.FindAliases (System.Collections.Generic.IEnumerable`1[T] assemblies) [0x00072] in <1a12afcf649f4de8ab5d15d82d4f6310>:0
at Cake.Core.Scripting.ScriptRunner.Run (Cake.Core.Scripting.IScriptHost host, Cake.Core.IO.FilePath scriptPath, System.Collections.Generic.IDictionary`2[TKey,TValue] arguments) [0x00238] in <1a12afcf649f4de8ab5d15d82d4f6310>:0
at Cake.Commands.BuildCommand.Execute (Cake.CakeOptions options) [0x0003f] in <52bc22bce5254240ba373b3cf23da1ab>:0
at Cake.CakeApplication.Run (Cake.CakeOptions options) [0x00015] in <52bc22bce5254240ba373b3cf23da1ab>:0
at Cake.Program.Main () [0x000d1] in <52bc22bce5254240ba373b3cf23da1ab>:0
```

Reproduce the failure with ZXing.Net.Mobile's build.sh and inspect tools/packages.config, then trace the reported failure through Cake.Core.Scripting.ScriptAliasFinder. Compare the loaded Cake.Core 0.28.0 with add-ins referencing 0.26.1. Done means the macOS build completes without the TypeLoadException and the compatibility warning is resolved or properly handled.

Written by the indexing model from the issue text.