Thank you for your post. We were successfully able to import AmazonIAP.unitypackage on Unity 3D v3.5.5 and Unity 3D v4.0.0 and did not face any issues. Please download the Amazon SDK again and retry importing the AmazonIAP.unitypackage. Hopefully this would resolve your issue. If you still face any issue, please raise a contact-us (
https://developer.amazon.com/help/contactus.html) with detailed explanation of your problem and one of our support engineer will assist you further.
Hi, We have tested a sample android app on Unity v4.0.12f on Windows platform by importing the AmazonIAP.unitypackage and were able to generate the AndroidManifest.xml successfully. Please follow the below steps to generate 1) Create a new Project from the "File" Menu. 2) Navigate to Build Settings under File Menu and Select the platform as Android. 3) Import AmazonIAP.unitypackage plugin into your project from "Assets -> Import Package -> Custom Package" menu. 4) Post import, Click on the Menu Bar and a new "Amazon" Menu would be added to the Menu bar. 5) Now you can generate the manifest file by selecting the "Generate AndroidManifest.xml " sub-menu under the "Amazon" Menu.
The issue is with version 3.5.7 (the latest and last 3.5.x Unity). Opening the package will fail and yield the error "Error while importing package: Package has unknown format". I have re-downloaded several times already to no avail. I'll see if I can open it up in 4.x beta and manually import it to 3.5.7.