我正在使用selenium和python客户端。在做selenium.delete_all_visible_cookies时，我得到例外：
错误：命令执行失败。 请在论坛搜索 http://clearspace.openqa.org表示错误 日志窗口中的详细信息。该 错误消息是：格式错误的URI 序列
日志窗口的错误是：
error(1254427481456): Exception details:
message -> malformed URI sequence,
fileName -> http://localhost:4444/selenium-server/core/scripts/selenium-browserbot.js,
lineNumber -> 1169,
stack ->
("WSS_GW",[object HTMLDocument])@http://localhost:4444/selenium-server/core/scripts/selenium-browserbot.js:1169
("WSS_GW",".mysite","/",[object HTMLDocument])@http://localhost:4444/selenium-server/core/scripts/selenium-browserbot.js:1208
("WSS_GW",".mysite","/",[object HTMLDocument])@http://localhost:4444/selenium-server/core/scripts/selenium-browserbot.js:1213
("WSS_GW",".mysite","/",[object HTMLDocument])@http://localhost:4444/selenium-server/core/scripts/selenium-browserbot.js:1236
("WSS_GW","mysite","/",[object XPCCrossOriginWrapper])@http://localhost:4444/selenium-server/core/scripts/selenium-browserbot.js:1248
("","")@http://localhost:4444/selenium-server/core/scripts/selenium-api.js:2607
("","")@http://localhost:4444/selenium-server/core/scripts/htmlutils.js:60
([object Object],[object Object])@http://localhost:4444/selenium-server/core/scripts/selenium-commandhandlers.js:310
()@http://localhost:4444/selenium-server/core/scripts/selenium-executionloop.js:112
(-10)@http://localhost:4444/selenium-server/core/scripts/selenium-executionloop.js:78
(-10)@http://localhost:4444/selenium-server/core/scripts/htmlutils.js:60 ,
name -> URIError
知道发生了什么事吗？