I have recently updated my Android Studio and I ran into this problem when trying to use an already working app that makes REST calls to my backend.
W/ActivityThread﹕ ClassLoader.loadClass: The class loader returned by Thread.getContextClassLoader() may fail for processes that host multiple applications. You should explicitly specify a context class loader. For example: Thread.setContextClassLoader(getClass().getClassLoader());
I am not sure what this means or where I should make the Thread.setContextClassLoader() call. Could it had been the Android Studio update?