Unity not being able to build to Android despite having the current android sdk installed.

In the Android Studio SDK manager, I checked every Version from 4.0 to 8.1, and downloaded them. The Path to those Files are E:\Users\Nicolai\AppData\Local\Android with Android being the SDK Folder.

However, when I try to build the Game in the Editor, I get this error thrown at me: CommandInvokationFailure: Unable to list target platforms. Please make sure the android sdk path is correct. E:/Users/Nicolai/AppData/Local/Android\tools\bin\avdmanager.bat list target -c

I tried several things including installing older Versions, resulting in Unity wanting a newer Version and reinstalling the SDK multiple times.

I am in desperate need of help for this problem, as I want to test my APP on an Android Phone. I am using Unity 2018.1.6f1 Personal Edition (64Bit) And I have a Project Set up for Android, exporting an empty project wont work as well.

Android SDK Tools is on version 26.1.1 Android SDK Platform-Tools is on version 28.0.0 Android SDK Build-Tools doesnt have a Version Field, but is named 28, so I suppose it's version 28. Android Emulator is on version 27.2.9 Intel x86 Emulator Accelerator is on version 7.2.0 Support Repository: Android Support Repository is on 47.0.0 Google Repository is on version 58

I don't know if you need this information, but that is everything I got installed in Android Studios SDK Tools Tab with the Version.

Thanks for your help in advance, if you need any more information just ask and I will promptly provide it.