I'm also trying to Debug a website on on iPad 10.3.4, in portrait mode, and getting the same exact messaging as in post #1 above. I've toggled the Web Inspector for Safari multiple times, restarted the device multiple times, both cable connected and not, restarted Safari on the Desktop multiple times. Nothing changes, still getting ‘No Inspectable Applications’ and then goes back to ‘Enable Web Inspector on Device’. Have to assume this is not compatible software: iPad 10.3.4 to Laptop 11.7 So nice to waste a huge amount of time. So, Apple, is this software too old? How about providing an intelligent message in the Develop menu, like "Software version not compatible", or such?