The current version of the Android BlinkUp SDK, 5.0.0, is not fully compatible with Android 6.0 Marshmallow. Attempting to build SDK-based apps in Android Studio when targeting Marshmallow will trigger the following error:
Warning: com.electricimp.blinkup.BlinkupHttpClient: can't find referenced method 'org.apache.http.params.HttpParams getParams()' in program class com.electricimp.blinkup.BlinkupHttpClient
We’re aware of the cause of the problem: the SDK requires Apache HttpClient, which is not included in Marshmallow. An updated version of the SDK which does not use Apache HttpClient is being prepared and will be released shortly. We’ll post a note here when it does.
You can also keep track of this issue on the Dec Center’s Known Issues page.