Restart is not required. Which AEM version are you trying. I will try once and let you know if its a problem with my instance aswell.Meanwhile, try on a new workflow model and see if you are still facing the issue.
For the default API to work, I believe the node should be available to create the properties. Instead as @scott mentioned, I would go with Typed APIs to handle this which gives much more control.
As rightly mentioned by @kautuk and @scott, you will get a 'Certificate of Completion' for each training you take for Developer, Advanced Developer, Administrator etc...You will have to take a diiferent exam for the product 'certification'
Hi Karel,You can overlay '/libs/cq/gui/components/common/tagspicker/clientlibs/tagspicker.js'and add a custom validation function to check for null and show a message respectively.