Fixture Builder bug - Yellow

I'm still having issues with adding a Yellow function in the fixture builder, currently on W10 v3.4.0
While it used to crash the desktop, (forums.highend.com/index.php?p=/discussion/14939/bug-report-1-2-0-fixture-builder#latest)
I now get an error message: "Build failed: Unable to retrieve object for ID 29 from functions array"
Removing the Yellow function allows the fixture to be built