Tomcat7 — Cannot create a server using the selected type

1.Go to Window–>Preferences–>Server–>Runtime Environments and fix the broken path/link for the server.
2.Rename the org.eclipse.jst.server.tomcat.core.prefs to org.eclipse.jst.server.tomcat.core.prefs.bak (or you can delete this file). This file can be found at \workspace\.metadata\.plugins\org.eclipse.core.runtime\.settings
Rename the org.eclipse.wst.server.core.prefs to org.eclipse.wst.server.core.prefs.bak (or delete the file). This file also can be found at the same location as above.

如果还不行，可以到第一步的地方新建服务器