Component dialog rendering not working in case of 404 response

To reproduce it, run attached project, ( channelmanager_freezes_with_empty_img_tag.zip ), open channel manager > myproject > events.
Click onto component block. Component dialog never initializes.
This is caused by an empty or any invalid image src attribute,

  <img src=""/>

or

  <img src="foo.jpg"/>

(I suspected it might be caused by the navapp but adding <img src="?iframe=true" /> doesn't solve the problem)

see:

*repository-data/webfiles/src/main/resources/site/freemarker/hstdefault/eventslist-main-eventslist.ftl