I have a multi-module maven project using Vaadin 7.5.8.
The following alert box is presented:
In ${ECLIPSE_WORKSPACE}/.metadata/.log:
!ENTRY com.vaadin.integration.eclipse 2 0 2015-10-27 02:19:26.907
!MESSAGE Could not check Vaadin version in project viki-common
!STACK 1
org.eclipse.core.runtime.CoreException: Unable to find WEB-INF/lib folder. Ensure the project is a dynamic web project.
at com.vaadin.integration.eclipse.util.ErrorUtil.newCoreException(ErrorUtil.java:141)
at com.vaadin.integration.eclipse.util.ProjectUtil.getWebInfLibFolder(ProjectUtil.java:110)
at com.vaadin.integration.eclipse.util.ProjectUtil.getVaadinLibraryInProject(ProjectUtil.java:376)
at com.vaadin.integration.eclipse.util.ProjectUtil.getVaadinLibraryVersion(ProjectUtil.java:351)
at com.vaadin.integration.eclipse.background.CheckVaadinVersionsJob.getVaadinProjects(CheckVaadinVersionsJob.java:100)
at com.vaadin.integration.eclipse.background.CheckVaadinVersionsJob.run(CheckVaadinVersionsJob.java:63)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)
!SUBENTRY 1 com.vaadin.integration.eclipse 4 0 2015-10-27 02:19:26.907
!MESSAGE Unable to find WEB-INF/lib folder. Ensure the project is a dynamic web project.
The interesting thing is that the project mentioned is closed at the time.