Selecting the Hierarchy Tab while loading a Concept view gives a 404 Error Page #713

At which URL did you encounter the problem?

http://skosmos.dev.finto.fi/agrovoc/en/index

What steps will reproduce the problem?

1. In alphabetical tab select a slow loading concept.
2. While it is still loading select the hierarchical tab.

What is the expected output? What do you see instead?

I would expect it to continue loading the concept selected an then display the hierarchy opened at the position of the selected concept. Or alternatively show the top level hierarchy, if available.

Instead, I get a 404 Error Page: "404 Error: The page /nomisma/en/page/?uri=undefined cannot be found."

What browser did you use? (eg. Firefox, Chrome, Safari, Internet explorer)

Firefox.