Unable to install some apps from Google Play on customized AOSP: Item is not available. Reason: 9

If you pull the Play Store APK from your device you can decompile it. I decompiled the APK and did a simple search for your error message. The error message can be found in the class com.google.android.finsky.utils.DocUtils

java

$ grep -lr "Item is not available"
com/google/android/finsky/utils/DocUtils.java

Here is the method:

public static int getAvailabilityRestrictionResourceId(Document document) {
    int restriction = document.getAvailabilityRestriction();
    int resourceId = R.string.availability_restriction_generic;
    switch (restriction) {
        case 2:
            resourceId = R.string.availability_restriction_country;
            break;
        case 8:
            resourceId = R.string.availability_restriction_not_in_group;
            break;
        case 9:
            if (document.getDocumentType() != 1) {
                resourceId = R.string.availability_restriction_hardware;
                break;
            }
            resourceId = R.string.availability_restriction_hardware_app;
            break;
        case 10:
            resourceId = R.string.availability_restriction_carrier;
            break;
        case 11:
            resourceId = R.string.availability_restriction_country_or_carrier;
            break;
        case 12:
            resourceId = R.string.availability_restriction_search_level;
            break;
        case 21:
            resourceId = R.string.availability_restriction_for_managed_account;
            break;
        case 22:
            resourceId = R.string.availability_restriction_missing_permission;
            break;
    }
    FinskyLog.d("Item is not available. Reason: " + restriction);
    return resourceId;
}

In your case, the response has a restriction of 9. This would either get one of two strings. If we decompile the resources of the APK using ApkTool we can see the values of these two strings.

xml

<string name="availability_restriction_hardware">"Your device isn't compatible with this item."</string>
<string name="availability_restriction_hardware_app">"Your device isn't compatible with this version."</string>

The method getAvailabilityRestrictionResourceId(Document document) is invoked in the following classes:

java

$ grep -lr getAvailabilityRestrictionResourceId | grep -v DocUtils
com/google/android/finsky/activities/AppsPermissionsActivity.java
com/google/android/finsky/billing/lightpurchase/OfferResolutionActivity.java
com/google/android/finsky/detailspage/WarningMessageModule.java
com/google/android/finsky/layout/WarningMessageSection.java

It would be beneficial if you provide info on when this gets logged.

The problem is still vague. From searching on Google, some people have solved similar problems by changing a system property (most often in /system/build.prop).

Probably not the answer your hoping for, but I hope my research helps out.