If by external editors, you mean other software plugins (like Photomatix, Nik products, etc), this always happens when a new edition of Lightroom or Photoshop is released. They have to update their software to be compatible with the new Adobe Products. It usually takes days to a few weeks depending on the product. You then have to download their update and install. For specific info, go to the software site. It's not a Lightroom problem....