Beginner question: How to install Vivide?

[LinqLover]

Hi, I wanted to try out this interesting project, but I have some trouble loading it.

After following the HowTo-Install and trying to open a Vivide Workspace in the new project, I get a fatal project error, caused by a DNU in ViToolWindow>>#updateBox:color: where anIconMorph is a UiToolButton that does not understand #useRoundedCorners. anIconMorph comes from an instvar named closeBox.

As I already had installed widgets (via WindowAcrobatics), I also followed the update instructions from FAQs and retried, but it did not help. Skipping the exception by returning a fake value failed as well, because I cannot switch back to the Vivide project after the fatal project error.

My image is based on SWT2019Trunk and has been updated within the past 14 days. In another SWT2019Trunk image (with less modifications/additional packages), Vivide works. However, the list of implementors of #useRoundedCorners is identical in both images.

Is there any short explanation for this problem?