I got the phone, what command are you using to install apks? I got a much longer error, and it didn't go through. I did
cd storage/self/primary/download
which went through, then
pm install filename.apk
which gave me
Exception occurred while executing 'install':
java.lang.IllegalArgumentException: Error: Can't open file: 2048.apk
at com.android.server.pm.PackageManagerShellCommand.setParamsSize(PackageManagerShellCommand.java:532)
at com.android.server.pm.PackageManagerShellCommand.doRunInstall(PackageManagerShellCommand.java:1295)
at com.android.server.pm.PackageManagerShellCommand.runInstall(PackageManagerShellCommand.java:1261)
at com.android.server.pm.PackageManagerShellCommand.onCommand(PackageManagerShellCommand.java:186)
at android.os.BasicShellCommandHandler.exec(BasicShellCommandHandler.java:98)
at android.os.ShellCommand.exec(ShellCommand.java:44)
at com.android.server.pm.PackageManagerService.onShellCommand(PackageManagerService.java:22037)
at android.os.Binder.shellCommand(Binder.java:929)
at android.os.Binder.onTransact(Binder.java:813)
at android.content.pm.IPackageManager$Stub.onTransact(IPackageManager.java:4603)
at com.android.server.pm.PackageManagerService.onTransact(PackageManagerService.java:4479)
at android.os.Binder.execTransactInternal(Binder.java:1159)
at android.os.Binder.execTransact(Binder.java:1123)
Is that because the command I used, or because I'm using WebADB