我通过安装这些文件来修复它：

• Eclipse Java EE开发工具


• Eclipse Java Web Developer Tools


• JST服务器适配器


• JST服务器适配器扩展

When creating a new Vaadin 7 project in eclipse I'm getting this error:

Failed while installing Dynamic Web Module 3.1

(see screenshot). Anyone knows why? The sources are not begin populated. I'm using Vaadin 7.3.6, Tomcat 8, Eclipse Luna Service Release 1 (4.4.1). Thanks for your help!

This is the error in the log

!ENTRY org.eclipse.jst.j2ee 4 0 2014-12-15 20:41:55.090 !MESSAGE No IModelProvider exists for project P/test of version: Dynamic Web Module 3.1 !STACK 0 java.lang.NullPointerException: No IModelProvider exists for project P/test of version: Dynamic Web Module 3.1

I fixed it by installing theses:

• Eclipse Java EE Developer Tools
• Eclipse Java Web Developer Tools
• JST Server Adapters
• JST Server Adapters Extensions