@kineret UIAutomation is deprecated for XCode 8.0 and later. You must launch Appium server with automation-name capability set as xcuitest. At the same time Appium 1.6 + XCode 8.0 is only compatible with iOS 9.3 or greater, for previous iOS versions you must use XCode 7 and automation-name set as UIAutomation (default I think).
Make sure that Appium is taking XCode 8.0 as its communication bridge with your device, may you have several XCode working in same computer.
Try to launch your Appium 1.6 server programatically from console and include --automation-name XCUITest to your usual desired capabilities.
appium --address 127.0.0.1 --port 4723 --platform-name ios --platform-version 10.0.1 --automation-name XCUITest --device-name s5 --udid db965483453320c02bb5907be3b02248b2f99576
Hope it helps.