error Google GWT

[Nadrahalshitwi]

Hello
I tried to install logicaldoc community edition on win 10 _64 bit andI follow these steps from
https://wiki.logicaldoc.com/wiki/Fast_and_Furious
and when I Compiling the web interface
I got this error

Errors occurred during the build.
Errors running builder 'GWT Project Validator' on project 'logicaldoc-gui'.
org.eclipse.jdt.internal.core.JavaProject.computePackageFragmentRoots([Lorg/eclipse/jdt/core/IClasspathEntry;ZLjava/util/Map;)[Lorg/eclipse/jdt/core/IPackageFragmentRoot;

Best Regards
Nadra