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Program type already present: android.support.annotation.AnimRes

This problem happened to me after i updated to the latest version of Xamarin.Forms (4.6.0)
I get this error whenever i try to build my Android Projects in Visual Studio For Mac (8.5.4)
What i tried so far:
Using different versions of the Android Support libraries
Cleaning my NuGet Cache
Reinstalling the SDK
Cleaning, Rebuilding, Restarting VS (several times)
Oddly i managed to get it working for a few builds after changing my support library versions from 28.0.0.3 to 28.0.0.1 manually in the csproj file. However i tried this several times and it doesn't solve the problem.
The problem occurs if i create a fresh Xamarin.Forms project aswell.
Any advice appreciated, as this is starting to be frustrating.

I don't know if this will help, but you should migrate to AndroidX as soon as possible, nevertheless. Xamarin has migrated to them, starting from Forms 4.5
Here is some more information about the libraries - Introducing AndroidX for Xamarin
There is a special NuGet package for the migration - Xamarin.AndroidX.Migration. Also available is a built-in functionality in Visual Studio - here
What I can suggest is you try to migrate to AndroidX libraries, since the old support libraries won't be supported from now on, and you will surely encounter some issues if not like this one, then something else will pop-up in the future.

How to connect Android TreeView library to my project?

This is a pretty newbie question.
I found a Polidea TreeView Library for Android.
But how do I use it for my project in Android Studio?
I've tried several things - adding the .jar files directly, importing as Project/Module, setting the dependencies in Gradle. But none of this worked.
Can anyone help me with this one?

Well, actually it turned out, that the best way of connecting this library - just copy src. It's easier, than messing up with Gradle.
In Eclipse everything works fine, by the way.

Cordova: Trouble importing Android Downloader_Library into project

I'm using Android Studio and I'm close to just canceling the Android version of my app and just sticking with the released iOS version. I need to use an expansion APK and I cannot for the life of me get the downloader_library to import into Android Studio.
I try and run the project and it says it can't find anything from the expansion downloader. I've tried everything I can find on the forums. I've tried bringing into Eclipse and exporting out. I just can't get this to work.
I don't know if I have some kind of fundamental misunderstanding about Android and libraries and modules and things but I'm about ready to give up on this unless someone has an easy way to help me through. This is the very last step. I have the IAB working, the app works on multiple devices, the performance is good, I just can't figure out this splitting of the APK.

Eclipse wizard no longer creates activities in Android projects

The exact problem described in this nine-month-old question suddenly (and apparently spontaneously) manifested for me today. It worked as recently as a few days ago. None of the answers on that older question solved the problem. In addition, I've tried updating all my Eclipse plugins to the latest versions, and tried creating a project in a clean new workspace. No dice
Has this happened to you recently? What is the solution?
(On a side note, can anyone explain why the most popular program used by programmers to write programs is such a complete piece of garbage? Grrr...)
Edit: After attempting to fix this via all the suggested methods, I have now also lost the ability to do Team > Revert... on any file or project. Yay! Looks like I'll be getting familiar with Android Studio this weekend.

Eclipse ADT: Project name "appcompat_v7" being created after creating every new project

Well I want to highlight this and bring it all in this thread, as the rest of threads did not have a concluded answer, so before skipping into them here are the threads I referred to:
Adt doesn't create default hello world but command line does
[solved ]Eclipse behaving differently while creating new project/activity
ADT has been behaving a bit weird since past few days. I keep my SDK always updated so I frequently Run the SDK manager and download all the updates. recently I noticed that if I create a new android app project it is not creating a default MainActivity even if I check that box, it does not create a Activity under src and more to annoy me, I wasnt able to refactor anything, so I realized that I had to update my Eclipse as after reading few posts, but now when I create every new project it creates an annoying appcompat_v7 project with EVERY project, say I create two new projects it creates appcompat_v7_2....this is driving me crazy and the new project library is the appcompat_v7 project. This is becoming annoying and no idea whats going on here !!!! What should I do...please rescue me ! Thanks in advance ....A screenshot to annoy u guys too ... :)
***************Current Alternative, not a solution***********************
As of 12/5/2014 with ADT 23.0.2 I dont see this issue anymore.
I have waited for an acceptable solution on this issue (as of now there is none), but one of the SO members directed me to this post https://code.google.com/p/android/issues/detail?id=66975. What I am doing is described in one of the solutions below, but for people who have come to this post, the alternative is to delete that ugly project(if you have more than one) which has been created and add up this one(appcompat_v7) as a library. So if you create another project and appcomat_v7_2...comes up delete that and point your project to the appcompat_v7, do the same for other projects too. This is not recommended for some reason though, but it worked well for me till now without issues. If anyone hits up with a solution please post it here.
****************Current Alternative, not a solution*****************************

the folder appcompat_v7 doesnt get created if i use
minSdkVersion="14"

Seems like it is a eclipse bug. What you need to do is go to properties in the of the Android Project and in the Android Section. Add the library appcompat_v7 and remove the appcompat_v_7_2 (duplicate). Then you can remove the appcompat_v7_2 as a eclipse project. All errors fixed.
Just a workaround.

The appcompat project is a library to support android's older versions. The support library was introduced by Google recently - I don´t know in which Android version.
But the point is, this project is only created when you create an Android project to cross Android platforms. I mean, when you select an old min API, e.g. API 8 (Froyo), but target recently versions, your project must have the support library.
Anyway, the creation of appcompat_v7 project is some issue that has to be better configured by the eclipse plugin maintainers. However you can elegantly turn over this issue by targeting newer APIs and including in the build path the support library. This is more elegant than the others because it is better to you focus in only one android version when building your application, and when it is done, you have an authentic version of your app that you can use as a mold to support other versions, either older or newers.