On Redmine 3.4.2, the click on "Triangle" doesn´t work

[carodrigues]

On Redmine 3.4.2, the click on "Triangle" doesn´t work

example:

This my system info:
(we have some plugins installed but, at the moment, we only have a open issue with workload)

[pierro78]

this is working for me with redmine 3.4.9 ...