解决Appium报错Requested a new session but one was in progress

报错信息如下：

error: Failed to start an Appium session, err was: Error: Requested a new sessio
n but one was in progress
info: [debug] Error: Requested a new session but one was in progress
    at [object Object].Appium.start (C:\Program Files (x86)\Appium\node_modules\
appium\lib\appium.js:139:15)
    at exports.createSession (C:\Program Files (x86)\Appium\node_modules\appium\
lib\server\controller.js:188:16)
    at Layer.handle [as handle_request] (C:\Program Files (x86)\Appium\node_modu
les\appium\node_modules\express\lib\router\layer.js:82:5)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:110:13)
    at Route.dispatch (C:\Program Files (x86)\Appium\node_modules\appium\node_mo
dules\express\lib\router\route.js:91:3)
    at Layer.handle [as handle_request] (C:\Program Files (x86)\Appium\node_modu
les\appium\node_modules\express\lib\router\layer.js:82:5)
    at C:\Program Files (x86)\Appium\node_modules\appium\node_modules\express\li
b\router\index.js:267:22
    at Function.proto.process_params (C:\Program Files (x86)\Appium\node_modules
\appium\node_modules\express\lib\router\index.js:321:12)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\index.js:261:10)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:100:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at C:\Program Files (x86)\Appium\node_modules\appium\lib\server\controller.j
s:39:7
    at Layer.handle [as handle_request] (C:\Program Files (x86)\Appium\node_modu
les\appium\node_modules\express\lib\router\layer.js:82:5)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:110:13)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\route.js:104:14)
    at Route.dispatch (C:\Program Files (x86)\Appium\node_modules\appium\node_mo
dules\express\lib\router\route.js:91:3)
    at Layer.handle [as handle_request] (C:\Program Files (x86)\Appium\node_modu
les\appium\node_modules\express\lib\router\layer.js:82:5)
    at C:\Program Files (x86)\Appium\node_modules\appium\node_modules\express\li
b\router\index.js:267:22
    at Function.proto.process_params (C:\Program Files (x86)\Appium\node_modules
\appium\node_modules\express\lib\router\index.js:321:12)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\index.js:261:10)
    at methodOverride (C:\Program Files (x86)\Appium\node_modules\appium\node_mo
dules\method-override\index.js:79:5)
    at Layer.handle [as handle_request] (C:\Program Files (x86)\Appium\node_modu
les\appium\node_modules\express\lib\router\layer.js:82:5)
    at trim_prefix (C:\Program Files (x86)\Appium\node_modules\appium\node_modul
es\express\lib\router\index.js:302:13)
    at C:\Program Files (x86)\Appium\node_modules\appium\node_modules\express\li
b\router\index.js:270:7
    at Function.proto.process_params (C:\Program Files (x86)\Appium\node_modules
\appium\node_modules\express\lib\router\index.js:321:12)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\index.js:261:10)
    at logger (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\mo
rgan\index.js:136:5)
    at Layer.handle [as handle_request] (C:\Program Files (x86)\Appium\node_modu
les\appium\node_modules\express\lib\router\layer.js:82:5)
    at trim_prefix (C:\Program Files (x86)\Appium\node_modules\appium\node_modul
es\express\lib\router\index.js:302:13)
    at C:\Program Files (x86)\Appium\node_modules\appium\node_modules\express\li
b\router\index.js:270:7
    at Function.proto.process_params (C:\Program Files (x86)\Appium\node_modules
\appium\node_modules\express\lib\router\index.js:321:12)
    at next (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\expr
ess\lib\router\index.js:261:10)
    at C:\Program Files (x86)\Appium\node_modules\appium\node_modules\body-parse
r\lib\read.js:111:5
    at done (C:\Program Files (x86)\Appium\node_modules\appium\node_modules\body
-parser\node_modules\raw-body\index.js:248:14)
    at IncomingMessage.onEnd (C:\Program Files (x86)\Appium\node_modules\appium\
node_modules\body-parser\node_modules\raw-body\index.js:294:7)
    at IncomingMessage.g (events.js:260:16)
    at emitNone (events.js:67:13)
    at IncomingMessage.emit (events.js:166:7)
    at endReadableNT (_stream_readable.js:893:12)
    at doNTCallback2 (node.js:429:9)
info: [debug] Responding to client with error: {"status":33,"value":{"message":"
A new session could not be created. (Original error: Requested a new session but
 one was in progress)","origValue":"Requested a new session but one was in progr
ess"},"sessionId":"4b2faefb-422b-4452-bf6b-ccb85a2f6e6d"}
info: <-- POST /wd/hub/session 500 3.646 ms - 250
undefined

 

问题原因：Appium responds with an error and then you start a new session. You need to call driver.quit() before you start a new session.

解决办法：Appium每次启动new session之前，使用driver.quit();