在Windows 7中创建extjs项目时，找到以下步骤和错误。
错误：
以下是我在windows cmd中输入的命令。我正在尝试在E：\ workspace中安装项目。但是它在名称中创建了一些文件夹但却引发了错误。
C:\Users\Testing_Valleycrest>sencha -sdk E:\extjs generate app account_manager E
:\workspace\test
Sencha Cmd v3.1.2.342
[INF]
[INF] init-plugin:
[INF]
[INF] -before-generate-workspace:
[INF]
[INF] cmd-root-plugin.init-properties:
[INF]
[INF] init-properties:
[INF]
[INF] init-sencha-command:
[INF]
[INF] init:
[INF]
[INF] generate-workspace-impl:
[INF] [echo] generating into E:\workspace\test from C:\Users\Testing_Valley
crest\bin\Sencha\Cmd\3.1.2.342/templates/workspace
[INF] [mkdir] Created dir: E:\workspace\test\packages
[INF]
[INF] cmd-root-plugin.copy-framework-to-workspace-impl:
[INF] [propertyfile] Updating property file: E:\workspace\test\.sencha\workspace
\sencha.cfg
[INF]
[INF] copy-framework-to-workspace-impl:
[INF] [copy] Copying 4522 files to E:\workspace\test\ext
[INF] [copy] Copying 89 files to E:\workspace\test\ext\src\ux
[INF] [propertyfile] Updating property file: E:\workspace\test\.sencha\workspace
\sencha.cfg
[INF]
[INF] copy-framework-to-workspace:
[INF]
[INF] generate-workspace:
[INF]
[INF] -after-generate-workspace:
[INF]
[INF] init-plugin:
[INF]
[INF] cmd-root-plugin.init-properties:
[INF]
[INF] init-properties:
[INF]
[INF] init-sencha-command:
[INF]
[INF] init:
[INF]
[INF] before-upgrade:
[INF]
[INF] generate-app-impl:
[INF]
[INF] generate-starter-app:
[INF] [mkdir] Created dir: E:\workspace\test\resources
[INF] [mkdir] Created dir: E:\workspace\test\overrides
[INF] [mkdir] Created dir: E:\workspace\test\sass\src
[INF] [mkdir] Created dir: E:\workspace\test\sass\var
[INF] [mkdir] Created dir: E:\workspace\test\sass\etc
[INF] [x-property-file] Updating property file: E:\workspace\test\.sencha\app\se
ncha.cfg
[INF]
[INF] after-upgrade:
[ERR]
[ERR] BUILD FAILED
[ERR] java.lang.NullPointerException
[ERR]
[ERR] Total time: 1 second
[ERR] com.sencha.exceptions.BasicException.