Automation Appium未成功执行代理服务器命令

我有：

[test_instagram.rb]

require 'rubygems'
require 'appium_lib'
appium_txt = 'E:\\Instagram\\appium.txt'
caps = Appium.load_appium_txt file: appium_txt, verbose: false
Appium::Driver.new(caps).start_driver
driver_quit

[appium.txt]

[caps]
platformName = "android"
app = "E:\\Instagram\\instagram.apk"
deviceName = "emulator-5554"
automationName = "Selendroid"

我已使用以下命令启动服务器：

节点--无重置--会话覆盖

当我运行ruby test\u instagram.rb时，应用程序在emulator（bluestack）中启动，然后发生以下错误：

C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/response.rb:51:in `assert_ok': Did not successfully proxy server command (Selenium::WebDriver::Error::UnknownError)
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/response.rb:15:in `initialize'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/http/common.rb:59:in `new'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/http/common.rb:59:in `create_response'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/http/default.rb:66:in `request'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/http/default.rb:64:in `request'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/http/common.rb:40:in `call'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/bridge.rb:634:in `raw_execute'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/bridge.rb:99:in `create_session'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/bridge.rb:68:in `initialize'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/common/driver.rb:33:in `new'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/common/driver.rb:33:in `for'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver.rb:67:in `for'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/appium_lib-4.0.0/lib/appium_lib/driver.rb:436:in `start_driver'
        from test_instagram.rb:22:in `<main>'

C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/response.rb:51:在“assert_ok”中：未成功执行代理服务器命令（selenium:：webdriver:：Error:：unknown错误）
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/response.rb:15:in'initialize'
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/http/common.rb:59:“新建”
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/http/common.rb:59:in“create_response”
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/http/default.rb:66:在“请求”中
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/http/default.rb:64:在“请求”中
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/http/common.rb:40:in'call'
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/bridge.rb:634:in'raw_execute'
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/bridge.rb:99:在“创建会话”中
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/remote/bridge.rb:68:in'initialize'
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/common/driver.rb:33:in'new'
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver/common/driver.rb:33:in'for'
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/selenium-webdriver-2.42.0/lib/selenium/webdriver.rb:67:in'for'
来自C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/appium_lib-4.0.0/lib/appium_lib/driver.rb:436:in'start_driver'
来自test_instagram.rb:22:in`'

问题是什么？如何解决