Multiselect vaadin addon component error

Support
#1

I follow the link Multiselect dropdown - CUBA.Platform

Tracing compile failure path for type 'java.util.InternalJsHashCodeMap'
[ERROR] Errors in 'com/google/gwt/emul/java/util/InternalJsHashCodeMap.java'
[ERROR] Line 120: The method elementAdded() is undefined for the type AbstractHashMap<K,V>
[ERROR] Line 137: The method elementRemoved() is undefined for the type AbstractHashMap<K,V>
Tracing compile failure path for type 'java.util.InternalJsStringMap'
[ERROR] Errors in 'com/google/gwt/emul/java/util/InternalJsStringMap.java'
[ERROR] Line 154: The method elementAdded() is undefined for the type AbstractHashMap<K,V>
[ERROR] Line 166: The method elementRemoved() is undefined for the type AbstractHashMap<K,V>
[ERROR] Aborting compile due to errors in some input files
:app-web-toolkit:buildWidgetSet FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app-web-toolkit:buildWidgetSet'.
> Process 'command 'C:\Program Files\Java\jdk1.8.0_144\bin\java.exe'' finished with non-zero exit value 1
#2

Hi,

It might be compatibility issue between the add-on and Vaadin version used in the platform. You should use add-on version compatible with Vaadin 7.7.