Particle Core is Offline since the Blynk public server went down

When I try to run an app I see the following message. It may be coincidence but this began after the recent Blynk server issues (2 or 3 weeks ago?).

This is a simple application running for a couple of months trouble free. Using a Redbear Duo (see for details) I created a bell application, that is, the Duo operates a servo from a single button in a Blynk app. I have recompiled this morning with the latest Blynk library (upgrading from 3.2 to 3.5) but it has made no difference.

The code can be see here:!Al4oDpCeXGBEjO4_xkFPmTiGjT32Sw

I would appreciate any pointers or suggestions to fix this.

Many thanks!

Are you sure you did that? Did you flash new version to particle?

I am as sure as the Particle Web Editor is. After clicking flash the status bar showed compiling and flashing and finally success. Is there a way I can check it was a success outside of Particle? The Duo leds pulse which means it is operating, but I cannot tell if it’s the original version, ie it has not flashed properly, or the updated version.


  1. Follow these steps
    Blynk apps stopped working on iPhone
  2. Post your serial monitor output
  3. Check if Blynk example sketch works for you at all.