I recently uploaded my project to Git, and used a auto-generated Xamarin/Windows/MacOS/VisualStudio .gitignore file. I did a lot of work and testing on iOS, but now I\'m com
In order to resolve this issue, I did following:
1) In my Xamarin.Forms project that was failing to build Android project, I removed all packages added by Xamarin.Forms package including Xamarin.forms package itself. In fact, I believe, you have to remove it first in order to remove others. Note you have to play bit to figure out which one will remove until you can remove its dependants. Simple thing to do!
2) Exit Xamarin Studio
3) I then went to my /Users/user_name/.local/share/Xamarin/Xamarin.Android.Support.v4/23.3.0.0/ directory and deleted whole zip folder and all Xamarin.Android.* folders (* is wild card for anyting)
4) Start Xamarin Studio
5) Delete all bin and obj directories in all projects of your solution (in my case Android, IOS and Xamarin.Forms projects)
6) Right click on Packages in your Android project, Add Package..., search for Xamarin.Forms and add it. This will add bunch of other dependant packages. In my case, following were added:
7) Clean All
8) Rebuild All
Before this, I was getting about 20 errors no matter what I try, all of them relating to Android.Support.Library.v4 and number of files missing in mine /Users/user_name/.local/share/Xamarin/Xamarin.Android.Support.v4/23.3.0.0/content and /Users/user_name/.local/share/Xamarin/Xamarin.Android.Support.v4/23.3.0.0/embedded directories. The error was along the lines "Please install package: 'Android Support Library' available in SDK installer."
If you are from Iran or other countries which are blocked by google, you will get these kinda errors because Xamarin can't dl the packages from google. in that case Please try deleting the zips folder, and any Android.Support.* folders from inside C:\Users\username\AppData\Local\Xamarin then try rebuild the android project after connecting to a VPN like https://www.betternet.co/.
The error message tells you pretty explicitly
what the error is
C:\Users\dev\AppData\Local\Xamarin\Android.Support.v4\21.0.3\android_m2repository_r10.zip is not a valid zip file
How to fix it
Please download https://dl-ssl.google.com/android/repository/android_m2repository_r10.zip and extract it to the C:\Users\dev\AppData\Local\Xamarin\Android.Support.v4\21.0.3\content directory.
I went through the same problem and I have just fixed using the following steps:
C:\Users\YOUR_USER\AppData\Local\Xamarin\zips\
C:\Users\YOUR_USER\AppData\Local\Xamarin\Xamarin.Android.*
Navigate to the directory of your solution and delete all the "bin" and "obj" folders
Make sure you have the latest Java SDK. In my case the latest one is JDK 1.8:
C:\Program Files\Java\jdk1.8.0_111
In my case I didn't have the latest java SDK so I searched in google for "Java SE Development Kit Downloads". It took me to the Oracle website page about "Java SE Development Kit 8 Downloads". I downloaded the file "jdk-8u111-windows-x64.exe" (194.64 MB). After the installation it created a folder "C:\Program Files\Java\jdk*\".
Make sure your Xamarin is pointing to this JDK:
In the Visual Studio go to "Tools -> Options -> Xamarin -> Android Settings -> Java Development Kit". In my case I set it to "C:\Program Files\Java\jdk1.8.0_111"
I hope it helps.
This problem usually occurs because of failing to download or install m2repository file.
You can try one of these three options:
1- You can let VS solves the problem it self. It can be done just by deleting (...\AppData\Local\Xamarin\Android.Support.v4)
directory and then rebuild the project. VS will download and install what it needs. If it does't work, go to number 2.
2- Manually Downloading android_m2repository_rnn.zip
and putting it into (...\AppData\Local\Xamarin\zips )
folder. VS will do the rest (including extracting and installing the file). You can download m2repositories from here:
https://dl-ssl.google.com/android/repository/android_m2repository_r33.zip
Just rename the number at the end of URL to what you need and then download the file.
Note: In some cases you might need to rename the file into it's MD5 hash of URL. (for me VS was a little stupid and doesn't do anything unless I renamed the m2repository file to it's MD5 hash).
Here is a list of some of MD5 hashes:
android_m2repository_r33.zip --> 5FB756A25962361D17BBE99C3B3FCC44.zip android_m2repository_r32.zip --> F16A3455987DBAE5783F058F19F7FCDF.zip android_m2repository_r31.zip --> 99A8907CE2324316E754A95E4C2D786E.zip android_m2repository_r30.zip --> 05AD180B8BDC7C21D6BCB94DDE7F2C8F.zip android_m2repository_r29.zip --> 2A3A8A6D6826EF6CC653030E7D695C41.zip android_m2repository_r28.zip --> 17BE247580748F1EDB72E9F374AA0223.zip android_m2repository_r27.zip --> C9FD4FCD69D7D12B1D9DF076B7BE4E1C.zip android_m2repository_r26.zip --> 8157FC1C311BB36420C1D8992AF54A4D.zip android_m2repository_r25.zip --> 0B3F1796C97C707339FB13AE8507AF50.zip android_m2repository_r24.zip --> 8E3C9EC713781EDFE1EFBC5974136BEA.zip android_m2repository_r23.zip --> D5BB66B3640FD9B9C6362C9DB5AB0FE7.zip android_m2repository_r22.zip --> 96659D653BDE0FAEDB818170891F2BB0.zip android_m2repository_r21.zip --> CD3223F2EFE068A26682B9E9C4B6FBB5.zip android_m2repository_r20.zip --> 650E58DF02DB1A832386FA4A2DE46B1A.zip android_m2repository_r19.zip --> 263B062D6EFAA8AEE39E9460B8A5851A.zip android_m2repository_r18.zip --> 25947AD38DCB4865ABEB61522FAFDA0E.zip android_m2repository_r17.zip --> 49054774F44AE5F35A6BA9D3C117EFD8.zip android_m2repository_r16.zip --> 0595E577D19D31708195A83087881EE6.zip
You can also find the list here: https://developer.xamarin.com/guides/android/troubleshooting/resolving-library-installation-errors/#Manually_Downloading_m2repository
3- Manually Downloading and Installing m2repository Files. The detailed process can be found here:
https://developer.xamarin.com/guides/android/troubleshooting/resolving-library-installation-errors/#Manually_Downloading_and_Installing_m2repository_Files
Sometimes the download packages to fail: